WorldWideScience

Sample records for vhs item number

  1. Sanitation of viral haemorrhagic septicaemia (VHS)

    DEFF Research Database (Denmark)

    Olesen, Niels Jørgen

    1998-01-01

    A sanitation programme for stamping-out viral haemorrhagic septicaemia (VHS) was implemented in Denmark in 1965. The programme has resulted in a dramatic reduction in the number of infected rainbow trout farms, from approximate to 400 to 26. The programme is carried out on a voluntary basis...

  2. Soviet Cybernetics: Recent News Items, Number Thirteen.

    Science.gov (United States)

    Holland, Wade B.

    An issue of "Soviet Cybernetics: Recent News Items" consists of English translations of the leading recent Soviet contributions to the study of cybernetics. Articles deal with cybernetics in the 21st Century; the Soviet State Committee on Science and Technology; economic reforms in Rudnev's ministry; an interview with Rudnev; Dnepr-2; Dnepr-2…

  3. An EPQ model with imperfect items using interval grey numbers

    Directory of Open Access Journals (Sweden)

    Erdal Aydemir

    2015-01-01

    Full Text Available The classic economic production quantity (EPQ model has been widely used to determine the optimal production quantity. However, the analysis for finding an EPQ model has many weaknesses which lead many researchers and practitioners to make extensions in several aspects on the original EPQ model. The basic assumption of EPQ model is that 100% of manufactured products are non-defective that is not valid for many production processes generally. The purpose of this paper is to develop an EPQ model with grey demand rate and cost values with maximum backorder level allowed with the good quality items in units under an imperfect production process. The imperfect items are considered to be low quality items which are sold to a particular purchaser at a lower price and, the others are reworked and scrapped. A mathematical model is developed and then an industrial example is presented on the wooden chipboard production process for illustration of the proposed model.

  4. Evaluating an Automated Number Series Item Generator Using Linear Logistic Test Models

    Directory of Open Access Journals (Sweden)

    Bao Sheng Loe

    2018-04-01

    Full Text Available This study investigates the item properties of a newly developed Automatic Number Series Item Generator (ANSIG. The foundation of the ANSIG is based on five hypothesised cognitive operators. Thirteen item models were developed using the numGen R package and eleven were evaluated in this study. The 16-item ICAR (International Cognitive Ability Resource1 short form ability test was used to evaluate construct validity. The Rasch Model and two Linear Logistic Test Model(s (LLTM were employed to estimate and predict the item parameters. Results indicate that a single factor determines the performance on tests composed of items generated by the ANSIG. Under the LLTM approach, all the cognitive operators were significant predictors of item difficulty. Moderate to high correlations were evident between the number series items and the ICAR test scores, with high correlation found for the ICAR Letter-Numeric-Series type items, suggesting adequate nomothetic span. Extended cognitive research is, nevertheless, essential for the automatic generation of an item pool with predictable psychometric properties.

  5. Retrieval of very large numbers of items in the Web of Science: an exercise to develop accurate search strategies

    NARCIS (Netherlands)

    Arencibia-Jorge, R.; Leydesdorff, L.; Chinchilla-Rodríguez, Z.; Rousseau, R.; Paris, S.W.

    2009-01-01

    The Web of Science interface counts at most 100,000 retrieved items from a single query. If the query results in a dataset containing more than 100,000 items the number of retrieved items is indicated as >100,000. The problem studied here is how to find the exact number of items in a query that

  6. Super VHS video cassette recorder, A-SB88; Super VHS video A-SB88

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    A super VHS video cassette recorder, A-SB88, was commercialized having no compromised aspects at all in picture quality, sound quality, operability, energy conservation, design, etc. In the picture quality, the VCR is mounted with the S-ET system capable of realizing a quality comparable to SVHS with a three-dimensional Y/C detached circuit for dynamic moving image detection, three-dimensional DNR(digital noise reduction) and TBC(time base corrector), FE(flying erase) circuit, and a normal tape. In the operability, it is provided with a remote control transfer in large LCD, 400x high speed rewind, reservation system capable of simply reserving a serial drama for example, and a function for searching the end of picture recording; also, in the environmental aspect, the stand-by power consumption was reduced to 1/10 of conventional models (ratio with Toshiba A-BS6 at display power off). (translated by NEDO)

  7. The Tipping Point: F-Score as a Function of the Number of Retrieved Items

    DEFF Research Database (Denmark)

    Guns, Raf; Lioma, Christina; Larsen, Birger

    2012-01-01

    One of the best known measures of information retrieval (IR) performance is the F-score, the harmonic mean of precision and recall. In this article we show that the curve of the F-score as a function of the number of retrieved items is always of the same shape: a fast concave increase to a maximu...

  8. Outbreak of viral haemorrhagic septicaemic (VHS) in seawater-farmed rainbow trout in Norway caused by VHS virus genotype III

    DEFF Research Database (Denmark)

    Dale, Ole Bendik; Ørpetveit, Irene; Lyngstad, Trude Marie

    2009-01-01

    with slightly elevated mortality was confirmed at a seawater site rearing rainbow trout (90 to 440 g). Within 3 to 4 mo, the disease was recognised in 3 neighbouring sea sites with on-growing rainbow trout. The clinical, gross pathological and histopathological findings were in accordance with VHS......, and the diagnosis was confirmed by the detection of VHSV in brain and internal tissues by immunohistochemistry, cell culture and reverse transcriptase PCR (RT-PCR). Sequence analysis of the G-gene revealed that the isolated virus clustered with VHSV Genotype III and that the Norwegian isolate represents a unique...

  9. Spatio-temporal risk factors for viral haemorrhagic septicaemia (VHS) in Danish aquaculture

    DEFF Research Database (Denmark)

    Jensen, Ann Britt Bang; Ersbøll, Annette Kjær; Korsholm, Henrik

    2014-01-01

    Viral haemorrhagic septicaemia (VHS) is an economically very important fish disease in the northern hemisphere. When the VHS virus was first isolated in Denmark 50 yr ago, more than 80% of the 800 Danish fish farms were considered to be infected, but vigilant surveillance and eradication programmes...

  10. Design of Web Questionnaires : A Test for Number of Items per Screen

    NARCIS (Netherlands)

    Toepoel, V.; Das, J.W.M.; van Soest, A.H.O.

    2005-01-01

    This paper presents results from an experimental manipulation of one versus multiple-items per screen format in a Web survey.The purpose of the experiment was to find out if a questionnaire s format influences how respondents provide answers in online questionnaires and if this is depending on

  11. Priority of VHS Development Based in Potential Area using Principal Component Analysis

    Science.gov (United States)

    Meirawan, D.; Ana, A.; Saripudin, S.

    2018-02-01

    The current condition of VHS is still inadequate in quality, quantity and relevance. The purpose of this research is to analyse the development of VHS based on the development of regional potential by using principal component analysis (PCA) in Bandung, Indonesia. This study used descriptive qualitative data analysis using the principle of secondary data reduction component. The method used is Principal Component Analysis (PCA) analysis with Minitab Statistics Software tool. The results of this study indicate the value of the lowest requirement is a priority of the construction of development VHS with a program of majors in accordance with the development of regional potential. Based on the PCA score found that the main priority in the development of VHS in Bandung is in Saguling, which has the lowest PCA value of 416.92 in area 1, Cihampelas with the lowest PCA value in region 2 and Padalarang with the lowest PCA value.

  12. Generalization of the Lord-Wingersky Algorithm to Computing the Distribution of Summed Test Scores Based on Real-Number Item Scores

    Science.gov (United States)

    Kim, Seonghoon

    2013-01-01

    With known item response theory (IRT) item parameters, Lord and Wingersky provided a recursive algorithm for computing the conditional frequency distribution of number-correct test scores, given proficiency. This article presents a generalized algorithm for computing the conditional distribution of summed test scores involving real-number item…

  13. VHS-tape system for general purpose computer. For next generation mass storage system

    International Nuclear Information System (INIS)

    Ukai, K.; Takano, M.; Shinohara, M.; Niki, K.; Suzuki, Y.; Hamada, T.; Ogawa, M.

    1994-07-01

    Mass storage is one of the key technology of next generation computer system. A huge amount of data is produced on a field of particle and nuclear physics. These data are raw data of experiments, analysis data, Monte Carlo simulations data, etc. We search a storage device for these data at the point of view of capacity, price, size, transfer speed, etc. We have selected a VHS-tape (12.7 mm-tape, helical scan) from many storage devices. Characteristics of the VHS-tape are as follows; capacity of 14.5 GB, size of 460 cm 3 , price of 1,000 yen (S-VHS tape for video use), and 1.996 MB/sec transfer speed at a sustained mode. Last year, we succeeded to operate the VHS-tape system on a workstation as a I/O device with read/write speed of 1.5 MB/sec. We have tested a VHS-tape system by connecting to the channel of the general purpose computer (Fujitsu M-780/10S) in our institute. We obtained a read and write speeds of 1.07 MB/sec and 1.72 MB/sec by FORTRAN test programs, respectively. Read speeds of an open reel tape and a 3480 type cassete tape by the same test programs are 1.13 MB/sec and 2.54 MB/sec, respectively. Speeds of write operation are 1.09 MB/sec and 2.54 MB/sec for the open reel and 3480 cassete tape, respectively. A start motion of the VHS-tape for read/write operations needs about 60 seconds. (author)

  14. First isolation and genotyping of viruses from recent outbreaks of viral haemorrhagic septicaemia (VHS) in Slovenia

    DEFF Research Database (Denmark)

    Toplak, Ivan; Hostnik, Peter; Rihtaric, Danijela

    2010-01-01

    and clinical signs of VHS were observed among the diseased fish. VHSV was confirmed by virus isolation, immunoperoxidase test, reverse transcriptase polymerase chain reaction (RT-PCR) and phylogenetic analysis. Based on 1 complete (1524 nucleotides [nt]) and 9 partial (600 nt) glycoprotein gene nucleotide...... sequences, 9 VHSV isolates from the 6 VHS outbreaks were genetically closely related (99 to 100% identity), and were classified into the Subgroup I-a of Genotype I, most closely related to the German isolates Dstg21-07, Dstg36-06, and Dstg54-1-07 (99 to 100% identity). Phylogenetic analysis...

  15. Design of a PLC control program for a batch plant : VHS case study 1

    NARCIS (Netherlands)

    Mader, A.H.; Brinksma, E.; Wupper, H.; Bauer, N.

    2001-01-01

    This article reports on the systematic design and validation of a PLC control program for the batch plant that has been selected as a case study for the EC project on Verification of Hybrid Systems (VHS). We show how a correct design of the control program can be obtained in an incremental manner

  16. Design of a PLC Control Program for a Batch Plant - VHS Case Study 1

    NARCIS (Netherlands)

    Mader, Angelika H.; Brinksma, Hendrik; Wupper, H.; Bauer, N.

    2001-01-01

    This article reports on the systematic design and validation of a PLC control program for the batch plant that has been selected as a case study for the EC project on Verification of Hybrid Systems (VHS). We show how a correct design of the control program can be obtained in an incremental manner

  17. Radiographic evaluation of the cardiac silluet using the VHS method (Vertebral Heart Size in young and adults coatis (Nasua nasua, Linneaus 1766 living in captivity

    Directory of Open Access Journals (Sweden)

    Andresa Cássia Martini

    2014-02-01

    Full Text Available Radiographic examination of the toracic cavity is an usefull noninvasive method for assessment, monitoring the progress of heart disease, suggesting prognosis and guiding the treatment. The aim of this study was to evaluate the cardiac silhouette of young and adults coatis and evaluate its relationship to the number of thoracic vertebrae (VHS, the method proposed by Buchanam and Buchele (1995 for small animals. We evaluated a group of 20 coatis, divided by age: I (GI and 8 animals aged between 4 and 5 months and group II (GII with 12 animals over 12 months old. Based in chest radiographs and VD laterolateral right projections for determining the major axis (L and short axis (Y being the sum of L and S is the value obtained by ESR, the relative depth/width (D / L chest were obtained and the results determined the type of conformation of the thorax, which results greater than 1.25 cm denote chest type deep, 0.75 to 1.25 cm chest intermediate and inferior results will 0.75cm wide chest. It was observed that the heart is alocated between the fourth and seventh pair of ribs, VHS average coatis healthy adults was 9.36 ± 0.75 and 8.06 ± 0 youth, 595 units thoracic vertebrae and the predominant conformation found was of intermediate type when compared to dogs. The mean values in this study serve as a basis for interpretation of the VHS type, however, a larger number may be required animals to determine the physiological limits of the cardiac silhouette in coati.

  18. Kan nye VHS udbrud i regnbueørred forebygges ved vaccination eller avl?

    DEFF Research Database (Denmark)

    Lorenzen, Niels

    laboratoriet ved forskellige temperaturer med godt resultat. En mindre afprøvning under dambrugsforhold har også givet gode resultater. Før det kan komme på tale bruge vaccinen ude, skal den dog godkendes af sundhedsmyndighederne. Egtvedsyge findes i flere lande i Europa og er kendt som en meget tabsvoldende......Tørlægning og desinfektion har traditionelt været brugt til at bekæmpe virussygdommen Egtvedsyge (VHS) i danske ørred-dambrug og lige nu regnes VHS for udryddet. Det har dog vist sig, at der hos vilde fiskebestande i havet findes VHS virus, som under visse omstændigheder må forventes at kunne...... koder for virusets overfladeprotein. Når plasmidet sprøjtes ind i en fisks rygmuskel, vil det blive optaget af en del af muskelcellerne på injektionsstedet, dog uden at plasmidets gener kommer ind i cellernes egne kromosomer. Fidusen er, at disse muskelceller herefter kan lave virusproteinet på samme...

  19. The Number of Response Categories and the Reverse Directional Item Problem in Likert-Type Scales: A Study with the Rasch Model

    Directory of Open Access Journals (Sweden)

    Mustafa İLHAN

    2017-09-01

    Full Text Available This study addressed reverse directional item and the number of response categories problems in Likert-type scales. The Fear of Negative Evaluation Scale (FNES and the Oxford Happiness Questionnaire (OHQ were used as data collection tools. The data of the study were analyzed according to the Rasch model. The analysis found that the observed and expected test characteristic curves were largely overlapped, each of the three rating scales worked effectively, and the differences between response categories could be distinguished successfully by the participants in straightforward directional items. On the other hand, it was determined that there were significant differences between the observed and expected test characteristic curves in reverse directional items. It was also found that no matter which one of these three, five and seven-point rating scales was used, the participants could not distinguish the response categories of the reverse directional items on the FNES and the OHQ. Afterwards, the reverse directional items were removed from the data file, and the analysis was repeated. The analysis results revealed that item discrimination, reliability coefficients for person facet, separation ratios and Chi square values calculated for the facets of person and items were higher in five-pointed rating compared to three and seven pointed rating.

  20. The herpes simplex virus 2 virion-associated ribonuclease vhs interferes with stress granule formation.

    Science.gov (United States)

    Finnen, Renée L; Hay, Thomas J M; Dauber, Bianca; Smiley, James R; Banfield, Bruce W

    2014-11-01

    In a previous study, it was observed that cells infected with herpes simplex virus 2 (HSV-2) failed to accumulate stress granules (SGs) in response to oxidative stress induced by arsenite treatment. As a follow-up to this observation, we demonstrate here that disruption of arsenite-induced SG formation by HSV-2 is mediated by a virion component. Through studies on SG formation in cells infected with HSV-2 strains carrying defective forms of UL41, the gene that encodes vhs, we identify vhs as a virion component required for this disruption. Cells infected with HSV-2 strains producing defective forms of vhs form SGs spontaneously late in infection. In addition to core SG components, these spontaneous SGs contain the viral immediate early protein ICP27 as well as the viral serine/threonine kinase Us3. As part of these studies, we reexamined the frameshift mutation known to reside within the UL41 gene of HSV-2 strain HG52. We demonstrate that this mutation is unstable and can rapidly revert to restore wild-type UL41 following low-multiplicity passaging. Identification of the involvement of virion-associated vhs in the disruption of SG formation will enable mechanistic studies on how HSV-2 is able to counteract antiviral stress responses early in infection. In addition, the ability of Us3 to localize to stress granules may indicate novel roles for this viral kinase in the regulation of translation. Eukaryotic cells respond to stress by rapidly shutting down protein synthesis and storing mRNAs in cytoplasmic stress granules (SGs). Stoppages in protein synthesis are problematic for all viruses as they rely on host cell machinery to synthesize viral proteins. Thus, many viruses target SGs for disruption or modification. Infection by herpes simplex virus 2 (HSV-2) was previously observed to disrupt SG formation induced by oxidative stress. In this follow-up study, we identify virion host shutoff protein (vhs) as a viral protein involved in this disruption. The

  1. Increasing the Number of Replications in Item Response Theory Simulations: Automation through SAS and Disk Operating System

    Science.gov (United States)

    Gagne, Phill; Furlow, Carolyn; Ross, Terris

    2009-01-01

    In item response theory (IRT) simulation research, it is often necessary to use one software package for data generation and a second software package to conduct the IRT analysis. Because this can substantially slow down the simulation process, it is sometimes offered as a justification for using very few replications. This article provides…

  2. Improving solubility and refolding efficiency of human V(H)s by a novel mutational approach.

    Science.gov (United States)

    Tanha, Jamshid; Nguyen, Thanh-Dung; Ng, Andy; Ryan, Shannon; Ni, Feng; Mackenzie, Roger

    2006-11-01

    The antibody V(H) domains of camelids tend to be soluble and to resist aggregation, in contrast to human V(H) domains. For immunotherapy, attempts have therefore been made to improve the properties of human V(H)s by camelization of a small set of framework residues. Here, we have identified through sequence comparison of well-folded llama V(H) domains an alternative set of residues (not typically camelid) for mutation. Thus, the solubility and thermal refolding efficiency of a typical human V(H), derived from the human antibody BT32/A6, were improved by introduction of two mutations in framework region (FR) 1 and 4 to generate BT32/A6.L1. Three more mutations in FR3 of BT32/A6.L1 further improved the thermal refolding efficiency while retaining solubility and cooperative melting profiles. To demonstrate practical utility, BT32/A6.L1 was used to construct a phage display library from which were isolated human V(H)s with good antigen binding activity and solubility. The engineered human V(H) domains described here may be useful for immunotherapy, due to their expected low immunogenicity, and in applications involving transient high temperatures, due to their efficient refolding after thermal denaturation.

  3. Recognition & Respect. Standards of Good Practice in the Employment of Graduate Employees. Item Number 36-0716

    Science.gov (United States)

    American Federation of Teachers, 2004

    2004-01-01

    A growing component of the instructional workforce in higher education, graduate teaching and research assistants are frequently viewed by university administrators and trustees as students rather than employees, according to this American Federation of Teachers (AFT) report. As the number of new full-time faculty hired decreases, an increased…

  4. Can VHS virus bypass the protective immunity induced by DNA vaccination in rainbow trout?

    DEFF Research Database (Denmark)

    Sepúlveda, Dagoberto; Lorenzen, Niels

    2016-01-01

    DNA vaccines encoding viral glycoproteins have been very successful for induction of protective immunity against diseases caused by rhabdoviruses in cultured fish species. However, the vaccine concept is based on a single viral gene and since RNA viruses are known to possess high variability...... and adaptation capacity, this work aimed at evaluating whether viral haemorrhagic septicaemia virus (VHSV), an RNA virus and member of Rhabdoviridae family, was able to evade the protective immune response induced by the DNA vaccination of rainbow trout. The experiments comprised repeated passages of a highly...... pathogenic VHSV isolate in a fish cell line in the presence of neutralizing fish serum (in vitro approach), and in rainbow trout immunized with the VHS DNA vaccine (in vivo approach). For the in vitro approach, the virus collected from the last passage (passaged virus) was as sensitive as the parental virus...

  5. Interference of an ERM-vaccine with a VHS-DNA vaccine in rainbow trout

    DEFF Research Database (Denmark)

    Lorenzen, Ellen; Einer-Jensen, Katja; Rasmussen, Jesper Skou

    Simultaneous vaccination of fish against several diseases is often desirable in order to minimise cost and handling of the fish. Intramuscular DNA-vaccination of rainbow trout against viral haemorrhagic septicaemia virus (VHSV) has proved to provide very good protection. However, preliminary...... results showed that intraperitoneal injection of a commercial vaccine against Enteric Redmouth Disease (ERM) based on formalin-killed bacteria in oil adjuvant immediately followed by intramuscular injection of an experimental DNA-vaccine against VHSV, decreased the protective effect of the DNA......-vaccine against challenge with VHSV 11 weeks post vaccination (pv). This experiment was performed with rainbow trout of 30 g injected with 0.5 g VHS-DNA vaccine. The experiment was later repeated with smaller fish (2.5g) and using two different doses of DNA-vaccine, 1 g and 0.05 g. Both doses provided good...

  6. Brain activity is related to individual differences in the number of items stored in auditory short-term memory for pitch: evidence from magnetoencephalography.

    Science.gov (United States)

    Grimault, Stephan; Nolden, Sophie; Lefebvre, Christine; Vachon, François; Hyde, Krista; Peretz, Isabelle; Zatorre, Robert; Robitaille, Nicolas; Jolicoeur, Pierre

    2014-07-01

    We used magnetoencephalography (MEG) to examine brain activity related to the maintenance of non-verbal pitch information in auditory short-term memory (ASTM). We focused on brain activity that increased with the number of items effectively held in memory by the participants during the retention interval of an auditory memory task. We used very simple acoustic materials (i.e., pure tones that varied in pitch) that minimized activation from non-ASTM related systems. MEG revealed neural activity in frontal, temporal, and parietal cortices that increased with a greater number of items effectively held in memory by the participants during the maintenance of pitch representations in ASTM. The present results reinforce the functional role of frontal and temporal cortices in the retention of pitch information in ASTM. This is the first MEG study to provide both fine spatial localization and temporal resolution on the neural mechanisms of non-verbal ASTM for pitch in relation to individual differences in the capacity of ASTM. This research contributes to a comprehensive understanding of the mechanisms mediating the representation and maintenance of basic non-verbal auditory features in the human brain. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Can VHS Virus Bypass the Protective Immunity Induced by DNA Vaccination in Rainbow Trout?

    Directory of Open Access Journals (Sweden)

    Dagoberto Sepúlveda

    Full Text Available DNA vaccines encoding viral glycoproteins have been very successful for induction of protective immunity against diseases caused by rhabdoviruses in cultured fish species. However, the vaccine concept is based on a single viral gene and since RNA viruses are known to possess high variability and adaptation capacity, this work aimed at evaluating whether viral haemorrhagic septicaemia virus (VHSV, an RNA virus and member of Rhabdoviridae family, was able to evade the protective immune response induced by the DNA vaccination of rainbow trout. The experiments comprised repeated passages of a highly pathogenic VHSV isolate in a fish cell line in the presence of neutralizing fish serum (in vitro approach, and in rainbow trout immunized with the VHS DNA vaccine (in vivo approach. For the in vitro approach, the virus collected from the last passage (passaged virus was as sensitive as the parental virus to serum neutralization, suggesting that the passaging did not promote the selection of virus populations able to bypass the neutralization by serum antibodies. Also, in the in vivo approach, where virus was passaged several times in vaccinated fish, no increased virulence nor increased persistence in vaccinated fish was observed in comparison with the parental virus. However, some of the vaccinated fish did get infected and could transmit the infection to naïve cohabitant fish. The results demonstrated that the DNA vaccine induced a robust protection, but also that the immunity was non-sterile. It is consequently important not to consider vaccinated fish as virus free in veterinary terms.

  8. Reducing the item number to obtain the same-length self-assessment scales: a systematic approach using result of graphical loglinear rasch models

    DEFF Research Database (Denmark)

    Nielsen, Tine; Kreiner, Svend

    2011-01-01

    The Revised Danish Learning Styles Inventory (R-D-LSI) (Nielsen 2005), which is an adaptation of Sternberg- Wagner Thinking Styles Inventory (Sternberg, 1997), comprises 14 subscales, each measuring a separate learning style. Of these 14 subscales, 9 are eight items long and 5 are seven items long...... Inventory (D-SA-LSI) comprising 14 subscales each with an item length of seven. The systematic approach to item reduction based on results of GLLRM will be presented and exemplified by its application to the R-D-LSI....

  9. Critical thinking analysis based on Facione (2015) – Angelo (1995) logical mathematics material of vocational high school (VHS)

    Science.gov (United States)

    Seventika, S. Y.; Sukestiyarno, Y. L.; Mariani, Scolastika

    2018-03-01

    The research has purpose to analyze and categorize the critical thinking ability of VHS students based on modified critical thinking indicator according to Facione-Angelo covering: interpreting the problem, analyzing alternative solution, applying the problem, evaluating the solution and concluding the results gained – attached by supportive evidence. The subject of the research is 30 eleventh graders of TKJ in Yabujah VHS, Indramayu in the odd semester 2016/2017. The collected data are critical thinking test and interviews. The result shows 15% is in good category, 30% in fair category, and 55% in low category. The students in “Good” category has accomplished critical thinking steps although imperfect, especially the indicators of evaluating and concluding attached by supportive evidence. The “Fair” categorized students only show partial steps of the indicators. The analyzing, evaluating, and concluding indicators are the most seldom to do, meanwhile the “low” categorized students show all indicators in low quality even to identify has problem to do.

  10. The Causality Study of External Environment Analysis (EEA), Internal Environment Analysis (IEA), Strategy Implementation on Study Program Performance at Vocational High School (VHS) in Nias Archipelago, Indonesia

    Science.gov (United States)

    Waruwu, Binahati; Sitompul, Harun; Manullang, Belferik

    2016-01-01

    The purposes of this study are to find out the significant effect of: (1) EEA on strategy implementation, (2) IEA on strategy implementation, (3) EEA on study program performance, (4) IEA on study program performance, and (5) strategy implementation on study program performance of Vocational High School (VHS) in Nias Archipelago. The population of…

  11. Cardiothoracic ratio and vertebral heart size (VHS to standardize the heart size of the tufted capuchin (Cebus apella Linnaeus, 1758 in computerized radiographic images

    Directory of Open Access Journals (Sweden)

    Hermínio J. Rocha-Neto

    2015-10-01

    Full Text Available Abstract: The VHS and CTR were assessed using computerized thoracic radiographs of ten clinically healthy tufted capuchin monkeys (five males and five females from the Wild Animal Screening Center in São Luís (Centro de Triagem de Animais Silvestres de São Luís-MA-CETAS. Radiographs were taken in laterolateral and dorsoventral projections to calculate the cardiothoracic ratio (VHS and vertebral heart size (CTR. The VHS showed mean values of 9.34±0.32v (males and 9.16±0.34v (females and there was no statistical difference between males and females (p>0.05. The CTR showed mean values of 0.55±0.04 (males and 0.52±0.03 (females and there was no statistical difference between the sexes (p>0.05. There was positive correlation between VHS and CTR (r=0.78. The thoracic and heart diameters showed mean values of 5.70±0.48cm and 2.16±0.40cm in the males, respectively. In the females they measured 5.32±0.39cm and 2.94±0.32cm. There was no statistical difference between the sexes. Our results show that the high correlation found between VHS and CTR permitted the verification with similar clinical precision between the two methods to estimate alterations in the heart silhouette by radiographic examination of tufted capuchin, making it an easy technique to apply that can be considered in the investigation of heart problems for this wild species.

  12. Item-focussed Trees for the Identification of Items in Differential Item Functioning.

    Science.gov (United States)

    Tutz, Gerhard; Berger, Moritz

    2016-09-01

    A novel method for the identification of differential item functioning (DIF) by means of recursive partitioning techniques is proposed. We assume an extension of the Rasch model that allows for DIF being induced by an arbitrary number of covariates for each item. Recursive partitioning on the item level results in one tree for each item and leads to simultaneous selection of items and variables that induce DIF. For each item, it is possible to detect groups of subjects with different item difficulties, defined by combinations of characteristics that are not pre-specified. The way a DIF item is determined by covariates is visualized in a small tree and therefore easily accessible. An algorithm is proposed that is based on permutation tests. Various simulation studies, including the comparison with traditional approaches to identify items with DIF, show the applicability and the competitive performance of the method. Two applications illustrate the usefulness and the advantages of the new method.

  13. VHS virus - present situation

    DEFF Research Database (Denmark)

    Skall, Helle Frank; Olesen, Niels Jørgen

    2015-01-01

    of the worldwide distribution of the disease will be given. Virus evolution: Recent studies indicate that only a few amino acid changes in the structural proteins of VHSV can change the virulence patterns significantly, thereby coming closer to assessing the risk of none to low virulent viruses becoming high...... virulent. Virulence factors both depend on the ability of VHSV to enter a cell and on the speed and efficiencyof virus replication in the cells. Apparently the viral nucleocapsid protein plays a very important role for the later and seems to be the target for determination of a virulence marker....

  14. Índices baseados no número de clientes para localização de itens em armazéns Indexes based on the number of customers to locate items in warehouse

    Directory of Open Access Journals (Sweden)

    Marcele Elisa Fontana

    2013-01-01

    Full Text Available Para se obter eficiência nas operações de armazenagem, um fator importante é estabelecer a política ótima de atribuição da localização dos itens em armazéns. Para tanto, um dos índices mais difundidos e utilizados é o cuber-per-order (COI. No entanto, observa-se que há situações em que o uso do COI pode concentrar vantagens para uma minoria de clientes. Nesse sentido, este artigo propõe verificar as consequências da utilização de índices alternativos (COIC e CIC, baseados no número de clientes que demandam cada tipo de produto (item, sobre o desempenho de um armazém em relação à utilização do COI. Conclui-se que considerar o número de clientes na determinação da política ótima de atribuição de locais aos itens armazenados proporciona uma maior vantagem competitiva, uma vez que um número maior de clientes pode ser beneficiado. Isso representa uma oportunidade de elevar o nível de serviço oferecido pelo armazém aos clientes.An important factor to obtain efficiency of storage operations is to establish an optimal policy for storage location assignment. To this end, one of the indexes more circulated and used is the Cuber-per-Order (COI. However, it is observed that there are situations where the use of COI can concentrate advantages to a minority of clients. In this sense, this paper proposes to verify the effects on the performance of a warehouse when using alternative indexes (COIC and CIC, based on the number of clients that require each type of product (item, compared to the COI. It was possible to conclude that when the number of clients is considered to determine optimal policy for storage location assignment, the warehouse can acquire a competitive advantage, since the largest number of clients can be benefited. This represents an opportunity to raise the service level offered by the warehouse to its clients.

  15. Using automatic item generation to create multiple-choice test items.

    Science.gov (United States)

    Gierl, Mark J; Lai, Hollis; Turner, Simon R

    2012-08-01

    Many tests of medical knowledge, from the undergraduate level to the level of certification and licensure, contain multiple-choice items. Although these are efficient in measuring examinees' knowledge and skills across diverse content areas, multiple-choice items are time-consuming and expensive to create. Changes in student assessment brought about by new forms of computer-based testing have created the demand for large numbers of multiple-choice items. Our current approaches to item development cannot meet this demand. We present a methodology for developing multiple-choice items based on automatic item generation (AIG) concepts and procedures. We describe a three-stage approach to AIG and we illustrate this approach by generating multiple-choice items for a medical licensure test in the content area of surgery. To generate multiple-choice items, our method requires a three-stage process. Firstly, a cognitive model is created by content specialists. Secondly, item models are developed using the content from the cognitive model. Thirdly, items are generated from the item models using computer software. Using this methodology, we generated 1248 multiple-choice items from one item model. Automatic item generation is a process that involves using models to generate items using computer technology. With our method, content specialists identify and structure the content for the test items, and computer technology systematically combines the content to generate new test items. By combining these outcomes, items can be generated automatically. © Blackwell Publishing Ltd 2012.

  16. Immunohistochemical detection of VHS virus in paraffin-embedded specimens of rainbow trout (Oncorhynchus mykiss); The influence of primary antibody, fixative, and antigen unmasking on method sensitivity

    DEFF Research Database (Denmark)

    Evensen, O.; Olesen, Niels Jørgen

    1997-01-01

    performed on parallel specimens, and the virus titer (TCID50/ml) was determined. Purified nucleocapsid protein (N-protein) of the virus was incorporated in an artificial antigen substrate (polymerized bovine serum albumin), fixed as described above, and embedded in paraffin wax. Microwave unmasking...... was performed an formalin-, PLP-, and Bouin's fluid-fixed specimens. The presence of virus peptides in situ or N-protein in the artificial antigen substrates was Visualized using an immunohistochemical method based on alkaline phosphatase or peroxidase and one polyclonal and five monoclonal polypeptide......-specific antibodies. VHS virus was identified in situ in specimens with high virus titers (10(7-8) TCID50/ml) regardless of the fixative and without the need of an unmasking procedure. A pronounced masking effect was observed for the cross-linking formalin and PLP fixatives. Regardless of the primary antibodies used...

  17. Grouping of Items in Mobile Web Questionnaires

    Science.gov (United States)

    Mavletova, Aigul; Couper, Mick P.

    2016-01-01

    There is some evidence that a scrolling design may reduce breakoffs in mobile web surveys compared to a paging design, but there is little empirical evidence to guide the choice of the optimal number of items per page. We investigate the effect of the number of items presented on a page on data quality in two types of questionnaires: with or…

  18. NHRIC (National Health Related Items Code)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The National Health Related Items Code (NHRIC) is a system for identification and numbering of marketed device packages that is compatible with other numbering...

  19. Kinetics of Mx expression in rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar L.) parr in response to VHS-DNA vaccination

    DEFF Research Database (Denmark)

    Acosta, F.; Petrie, A.; Lockhart, K.

    2005-01-01

    vaccine or the synthetic double-stranded RNA, poly LC. In both species there was a rapid response to poly LC detectable from day 1, reaching maximum from days 3 to 9 and decreasing to background level by day 12. The peak level and return to background was reached slightly later in salmon. In both species...... the response to the VHS/DNA vaccine was slower to begin, not being detectable on days 1 and 3, but elevated levels were found on day 6. However, in the salmon part, the peak level was on day 6 and the signal disappeared by day 12, while in the rainbow trout, the response peaked at day 12 and lasted until day......The duration of the Mx mRNA response to an intramuscular injection of the viral haemorrhagic septicaemia virus (VHSV) glycoprotein (G) gene DNA vaccine as well as to the control plasmid was determined in rainbow trout at 14 degreesC over a period of 11 weeks. The Mx response was detectable on day 7...

  20. Evolution of a Test Item

    Science.gov (United States)

    Spaan, Mary

    2007-01-01

    This article follows the development of test items (see "Language Assessment Quarterly", Volume 3 Issue 1, pp. 71-79 for the article "Test and Item Specifications Development"), beginning with a review of test and item specifications, then proceeding to writing and editing of items, pretesting and analysis, and finally selection of an item for a…

  1. Assessing difference between classical test theory and item ...

    African Journals Online (AJOL)

    Assessing difference between classical test theory and item response theory methods in scoring primary four multiple choice objective test items. ... All research participants were ranked on the CTT number correct scores and the corresponding IRT item pattern scores from their performance on the PRISMADAT. Wilcoxon ...

  2. SHIPPING OF RADIOACTIVE ITEMS

    CERN Multimedia

    TIS/RP Group

    2001-01-01

    The TIS-RP group informs users that shipping of small radioactive items is normally guaranteed within 24 hours from the time the material is handed in at the TIS-RP service. This time is imposed by the necessary procedures (identification of the radionuclides, determination of dose rate and massive objects require a longer procedure and will therefore take longer.

  3. Spare Items validation

    International Nuclear Information System (INIS)

    Fernandez Carratala, L.

    1998-01-01

    There is an increasing difficulty for purchasing safety related spare items, with certifications by manufacturers for maintaining the original qualifications of the equipment of destination. The main reasons are, on the top of the logical evolution of technology, applied to the new manufactured components, the quitting of nuclear specific production lines and the evolution of manufacturers quality systems, originally based on nuclear codes and standards, to conventional industry standards. To face this problem, for many years different Dedication processes have been implemented to verify whether a commercial grade element is acceptable to be used in safety related applications. In the same way, due to our particular position regarding the spare part supplies, mainly from markets others than the american, C.N. Trillo has developed a methodology called Spare Items Validation. This methodology, which is originally based on dedication processes, is not a single process but a group of coordinated processes involving engineering, quality and management activities. These are to be performed on the spare item itself, its design control, its fabrication and its supply for allowing its use in destinations with specific requirements. The scope of application is not only focussed on safety related items, but also to complex design, high cost or plant reliability related components. The implementation in C.N. Trillo has been mainly curried out by merging, modifying and making the most of processes and activities which were already being performed in the company. (Author)

  4. Selecting Lower Priced Items.

    Science.gov (United States)

    Kleinert, Harold L.; And Others

    1988-01-01

    A program used to teach moderately to severely mentally handicapped students to select the lower priced items in actual shopping activities is described. Through a five-phase process, students are taught to compare prices themselves as well as take into consideration variations in the sizes of containers and varying product weights. (VW)

  5. The Role of Item Models in Automatic Item Generation

    Science.gov (United States)

    Gierl, Mark J.; Lai, Hollis

    2012-01-01

    Automatic item generation represents a relatively new but rapidly evolving research area where cognitive and psychometric theories are used to produce tests that include items generated using computer technology. Automatic item generation requires two steps. First, test development specialists create item models, which are comparable to templates…

  6. Item information and discrimination functions for trinary PCM items

    NARCIS (Netherlands)

    Akkermans, Wies; Muraki, Eiji

    1997-01-01

    For trinary partial credit items the shape of the item information and the item discrimination function is examined in relation to the item parameters. In particular, it is shown that these functions are unimodal if δ2 – δ1 < 4 ln 2 and bimodal otherwise. The locations and values of the maxima are

  7. Item response theory - A first approach

    Science.gov (United States)

    Nunes, Sandra; Oliveira, Teresa; Oliveira, Amílcar

    2017-07-01

    The Item Response Theory (IRT) has become one of the most popular scoring frameworks for measurement data, frequently used in computerized adaptive testing, cognitively diagnostic assessment and test equating. According to Andrade et al. (2000), IRT can be defined as a set of mathematical models (Item Response Models - IRM) constructed to represent the probability of an individual giving the right answer to an item of a particular test. The number of Item Responsible Models available to measurement analysis has increased considerably in the last fifteen years due to increasing computer power and due to a demand for accuracy and more meaningful inferences grounded in complex data. The developments in modeling with Item Response Theory were related with developments in estimation theory, most remarkably Bayesian estimation with Markov chain Monte Carlo algorithms (Patz & Junker, 1999). The popularity of Item Response Theory has also implied numerous overviews in books and journals, and many connections between IRT and other statistical estimation procedures, such as factor analysis and structural equation modeling, have been made repeatedly (Van der Lindem & Hambleton, 1997). As stated before the Item Response Theory covers a variety of measurement models, ranging from basic one-dimensional models for dichotomously and polytomously scored items and their multidimensional analogues to models that incorporate information about cognitive sub-processes which influence the overall item response process. The aim of this work is to introduce the main concepts associated with one-dimensional models of Item Response Theory, to specify the logistic models with one, two and three parameters, to discuss some properties of these models and to present the main estimation procedures.

  8. Item Banking with Embedded Standards

    Science.gov (United States)

    MacCann, Robert G.; Stanley, Gordon

    2009-01-01

    An item banking method that does not use Item Response Theory (IRT) is described. This method provides a comparable grading system across schools that would be suitable for low-stakes testing. It uses the Angoff standard-setting method to obtain item ratings that are stored with each item. An example of such a grading system is given, showing how…

  9. SHIPPING OF RADIOACTIVE ITEMS

    CERN Multimedia

    TIS/RP Group

    2001-01-01

    The TIS-RP group informs users that shipping of small radioactive items is normally guaranteed within 24 hours from the time the material is handed in at the TIS-RP service. This time is imposed by the necessary procedures (identification of the radionuclides, determination of dose rate, preparation of the package and related paperwork). Large and massive objects require a longer procedure and will therefore take longer.

  10. Item selection via Bayesian IRT models.

    Science.gov (United States)

    Arima, Serena

    2015-02-10

    With reference to a questionnaire that aimed to assess the quality of life for dysarthric speakers, we investigate the usefulness of a model-based procedure for reducing the number of items. We propose a mixed cumulative logit model, which is known in the psychometrics literature as the graded response model: responses to different items are modelled as a function of individual latent traits and as a function of item characteristics, such as their difficulty and their discrimination power. We jointly model the discrimination and the difficulty parameters by using a k-component mixture of normal distributions. Mixture components correspond to disjoint groups of items. Items that belong to the same groups can be considered equivalent in terms of both difficulty and discrimination power. According to decision criteria, we select a subset of items such that the reduced questionnaire is able to provide the same information that the complete questionnaire provides. The model is estimated by using a Bayesian approach, and the choice of the number of mixture components is justified according to information criteria. We illustrate the proposed approach on the basis of data that are collected for 104 dysarthric patients by local health authorities in Lecce and in Milan. Copyright © 2014 John Wiley & Sons, Ltd.

  11. Constructing the 32-item Fitness-to-Drive Screening Measure.

    Science.gov (United States)

    Medhizadah, Shabnam; Classen, Sherrilene; Johnson, Andrew M

    2018-04-01

    The Fitness-to-Drive Screening Measure © (FTDS) enables proxies to identify at-risk older drivers via 54 driving-related items, but may be too lengthy for widespread uptake. We reduced the number of items in the FTDS and validated the shorter measure, using 200 caregiver responses. Exploratory factor analysis and classical test theory techniques were used to determine the most interpretable factor model and the minimum number of items to be used for predicting fitness to drive. The extent to which the shorter FTDS predicted the results of the 54-item FTDS was evaluated through correlational analysis. A three-factor model best represented the empirical data. Classical test theory techniques lead to the development of the 32-item FTDS. The 32-item FTDS was highly correlated ( r = .99, p = .05) with the FTDS. The 32-item FTDS may provide raters with a faster and more efficient way to identify at-risk older drivers.

  12. Negative effects of item repetition on source memory.

    Science.gov (United States)

    Kim, Kyungmi; Yi, Do-Joon; Raye, Carol L; Johnson, Marcia K

    2012-08-01

    In the present study, we explored how item repetition affects source memory for new item-feature associations (picture-location or picture-color). We presented line drawings varying numbers of times in Phase 1. In Phase 2, each drawing was presented once with a critical new feature. In Phase 3, we tested memory for the new source feature of each item from Phase 2. Experiments 1 and 2 demonstrated and replicated the negative effects of item repetition on incidental source memory. Prior item repetition also had a negative effect on source memory when different source dimensions were used in Phases 1 and 2 (Experiment 3) and when participants were explicitly instructed to learn source information in Phase 2 (Experiments 4 and 5). Importantly, when the order between Phases 1 and 2 was reversed, such that item repetition occurred after the encoding of critical item-source combinations, item repetition no longer affected source memory (Experiment 6). Overall, our findings did not support predictions based on item predifferentiation, within-dimension source interference, or general interference from multiple traces of an item. Rather, the findings were consistent with the idea that prior item repetition reduces attention to subsequent presentations of the item, decreasing the likelihood that critical item-source associations will be encoded.

  13. Gender-Based Differential Item Performance in Mathematics Achievement Items.

    Science.gov (United States)

    Doolittle, Allen E.; Cleary, T. Anne

    1987-01-01

    Eight randomly equivalent samples of high school seniors were each given a unique form of the ACT Assessment Mathematics Usage Test (ACTM). Signed measures of differential item performance (DIP) were obtained for each item in the eight ACTM forms. DIP estimates were analyzed and a significant item category effect was found. (Author/LMO)

  14. Item validity vs. item discrimination index: a redundancy?

    Science.gov (United States)

    Panjaitan, R. L.; Irawati, R.; Sujana, A.; Hanifah, N.; Djuanda, D.

    2018-03-01

    In several literatures about evaluation and test analysis, it is common to find that there are calculations of item validity as well as item discrimination index (D) with different formula for each. Meanwhile, other resources said that item discrimination index could be obtained by calculating the correlation between the testee’s score in a particular item and the testee’s score on the overall test, which is actually the same concept as item validity. Some research reports, especially undergraduate theses tend to include both item validity and item discrimination index in the instrument analysis. It seems that these concepts might overlap for both reflect the test quality on measuring the examinees’ ability. In this paper, examples of some results of data processing on item validity and item discrimination index were compared. It would be discussed whether item validity and item discrimination index can be represented by one of them only or it should be better to present both calculations for simple test analysis, especially in undergraduate theses where test analyses were included.

  15. Identify, Organize, and Retrieve Items Using Zotero

    Science.gov (United States)

    Clark, Brian; Stierman, John

    2009-01-01

    Librarians build collections. To do this they use tools that help them identify, organize, and retrieve items for the collection. Zotero (zoh-TAIR-oh) is such a tool that helps the user build a library of useful books, articles, web sites, blogs, etc., discovered while surfing online. A visit to Zotero's homepage, www.zotero.org, shows a number of…

  16. Quantum partial search for uneven distribution of multiple target items

    Science.gov (United States)

    Zhang, Kun; Korepin, Vladimir

    2018-06-01

    Quantum partial search algorithm is an approximate search. It aims to find a target block (which has the target items). It runs a little faster than full Grover search. In this paper, we consider quantum partial search algorithm for multiple target items unevenly distributed in a database (target blocks have different number of target items). The algorithm we describe can locate one of the target blocks. Efficiency of the algorithm is measured by number of queries to the oracle. We optimize the algorithm in order to improve efficiency. By perturbation method, we find that the algorithm runs the fastest when target items are evenly distributed in database.

  17. Redesigning Schools to Raise Achievement. Item Number 39-0464

    Science.gov (United States)

    American Federation of Teachers, 2003

    2003-01-01

    The primary goal of the American Federation of Teachers' (AFT) Redesigning Schools to Raise Achievement (RSRA) project is to build capacity at the state, district, school, and classroom levels to improve student achievement to meet the goals of the 2001 No Child Left Behind Act. This checklist highlights some of the opportunities and support…

  18. Problems with the factor analysis of items: Solutions based on item response theory and item parcelling

    Directory of Open Access Journals (Sweden)

    Gideon P. De Bruin

    2004-10-01

    Full Text Available The factor analysis of items often produces spurious results in the sense that unidimensional scales appear multidimensional. This may be ascribed to failure in meeting the assumptions of linearity and normality on which factor analysis is based. Item response theory is explicitly designed for the modelling of the non-linear relations between ordinal variables and provides a strong alternative to the factor analysis of items. Items may also be combined in parcels that are more likely to satisfy the assumptions of factor analysis than do the items. The use of the Rasch rating scale model and the factor analysis of parcels is illustrated with data obtained with the Locus of Control Inventory. The results of these analyses are compared with the results obtained through the factor analysis of items. It is shown that the Rasch rating scale model and the factoring of parcels produce superior results to the factor analysis of items. Recommendations for the analysis of scales are made. Opsomming Die faktorontleding van items lewer dikwels misleidende resultate op, veral in die opsig dat eendimensionele skale as meerdimensioneel voorkom. Hierdie resultate kan dikwels daaraan toegeskryf word dat daar nie aan die aannames van lineariteit en normaliteit waarop faktorontleding berus, voldoen word nie. Itemresponsteorie, wat eksplisiet vir die modellering van die nie-liniêre verbande tussen ordinale items ontwerp is, bied ’n aantreklike alternatief vir die faktorontleding van items. Items kan ook in pakkies gegroepeer word wat meer waarskynlik aan die aannames van faktorontleding voldoen as individuele items. Die gebruik van die Rasch beoordelingskaalmodel en die faktorontleding van pakkies word aan die hand van data wat met die Lokus van Beheervraelys verkry is, gedemonstreer. Die resultate van hierdie ontledings word vergelyk met die resultate wat deur ‘n faktorontleding van die individuele items verkry is. Die resultate dui daarop dat die Rasch

  19. Counterfeit and Fraudulent Items - Mitigating the risk

    International Nuclear Information System (INIS)

    Tannenbaum, Marc

    2011-01-01

    This presentation (slides) provides an overview of the industry's challenges and activities. Firstly, it outlines the differences between counterfeit, fraudulent, suspect, and also substandard items. Notice is given that items could be found not to meet the standard, but the difference in the intent to deceive with counterfeit and fraudulent items is the critical element. Examples from other industries are used which also rely heavily on the assurance of quality for safety. It also informs that EPRI has just completed a report in October 2009 in coordination with other US government agencies and industry organizations; this report, entitled Counterfeit, Substandard and Fraudulent Items, number 1019163, is available for free on the EPRI web site. As a follow-up to this report, EPRI is developing a CFSI Database; any country interested in a collaborative agreement is invited to use and contribute to the database information. Finally, it stresses the importance of the oversight of contractors, training to raise the awareness of the employees and the inspectors, and having a response plan for identified items

  20. ITEM LEVEL DIAGNOSTICS AND MODEL - DATA FIT IN ITEM ...

    African Journals Online (AJOL)

    Global Journal

    Item response theory (IRT) is a framework for modeling and analyzing item response ... data. Though, there is an argument that the evaluation of fit in IRT modeling has been ... National Council on Measurement in Education ... model data fit should be based on three types of ... prediction should be assessed through the.

  1. Item Response Data Analysis Using Stata Item Response Theory Package

    Science.gov (United States)

    Yang, Ji Seung; Zheng, Xiaying

    2018-01-01

    The purpose of this article is to introduce and review the capability and performance of the Stata item response theory (IRT) package that is available from Stata v.14, 2015. Using a simulated data set and a publicly available item response data set extracted from Programme of International Student Assessment, we review the IRT package from…

  2. MIMIC Methods for Assessing Differential Item Functioning in Polytomous Items

    Science.gov (United States)

    Wang, Wen-Chung; Shih, Ching-Lin

    2010-01-01

    Three multiple indicators-multiple causes (MIMIC) methods, namely, the standard MIMIC method (M-ST), the MIMIC method with scale purification (M-SP), and the MIMIC method with a pure anchor (M-PA), were developed to assess differential item functioning (DIF) in polytomous items. In a series of simulations, it appeared that all three methods…

  3. Detection of differential item functioning using Lagrange multiplier tests

    NARCIS (Netherlands)

    Glas, Cornelis A.W.

    1996-01-01

    In this paper it is shown that differential item functioning can be evaluated using the Lagrange multiplier test or C. R. Rao's efficient score test. The test is presented in the framework of a number of item response theory (IRT) models such as the Rasch model, the one-parameter logistic model, the

  4. Loglinear multidimensional IRT models for polytomously scored items

    NARCIS (Netherlands)

    Kelderman, Henk; Rijkes, Carl P.M.; Rijkes, Carl

    1994-01-01

    A loglinear IRT model is proposed that relates polytomously scored item responses to a multidimensional latent space. The analyst may specify a response function for each response, indicating which latent abilities are necessary to arrive at that response. Each item may have a different number of

  5. Negative effects of item repetition on source memory

    OpenAIRE

    Kim, Kyungmi; Yi, Do-Joon; Raye, Carol L.; Johnson, Marcia K.

    2012-01-01

    In the present study, we explored how item repetition affects source memory for new item–feature associations (picture–location or picture–color). We presented line drawings varying numbers of times in Phase 1. In Phase 2, each drawing was presented once with a critical new feature. In Phase 3, we tested memory for the new source feature of each item from Phase 2. Experiments 1 and 2 demonstrated and replicated the negative effects of item repetition on incidental source memory. Prior item re...

  6. Data Visualization of Item-Total Correlation by Median Smoothing

    Directory of Open Access Journals (Sweden)

    Chong Ho Yu

    2016-02-01

    Full Text Available This paper aims to illustrate how data visualization could be utilized to identify errors prior to modeling, using an example with multi-dimensional item response theory (MIRT. MIRT combines item response theory and factor analysis to identify a psychometric model that investigates two or more latent traits. While it may seem convenient to accomplish two tasks by employing one procedure, users should be cautious of problematic items that affect both factor analysis and IRT. When sample sizes are extremely large, reliability analyses can misidentify even random numbers as meaningful patterns. Data visualization, such as median smoothing, can be used to identify problematic items in preliminary data cleaning.

  7. Selecting Items for Criterion-Referenced Tests.

    Science.gov (United States)

    Mellenbergh, Gideon J.; van der Linden, Wim J.

    1982-01-01

    Three item selection methods for criterion-referenced tests are examined: the classical theory of item difficulty and item-test correlation; the latent trait theory of item characteristic curves; and a decision-theoretic approach for optimal item selection. Item contribution to the standardized expected utility of mastery testing is discussed. (CM)

  8. Random selection of items. Selection of n1 samples among N items composing a stratum

    International Nuclear Information System (INIS)

    Jaech, J.L.; Lemaire, R.J.

    1987-02-01

    STR-224 provides generalized procedures to determine required sample sizes, for instance in the course of a Physical Inventory Verification at Bulk Handling Facilities. The present report describes procedures to generate random numbers and select groups of items to be verified in a given stratum through each of the measurement methods involved in the verification. (author). 3 refs

  9. Evaluating the quality of medical multiple-choice items created with automated processes.

    Science.gov (United States)

    Gierl, Mark J; Lai, Hollis

    2013-07-01

    Computerised assessment raises formidable challenges because it requires large numbers of test items. Automatic item generation (AIG) can help address this test development problem because it yields large numbers of new items both quickly and efficiently. To date, however, the quality of the items produced using a generative approach has not been evaluated. The purpose of this study was to determine whether automatic processes yield items that meet standards of quality that are appropriate for medical testing. Quality was evaluated firstly by subjecting items created using both AIG and traditional processes to rating by a four-member expert medical panel using indicators of multiple-choice item quality, and secondly by asking the panellists to identify which items were developed using AIG in a blind review. Fifteen items from the domain of therapeutics were created in three different experimental test development conditions. The first 15 items were created by content specialists using traditional test development methods (Group 1 Traditional). The second 15 items were created by the same content specialists using AIG methods (Group 1 AIG). The third 15 items were created by a new group of content specialists using traditional methods (Group 2 Traditional). These 45 items were then evaluated for quality by a four-member panel of medical experts and were subsequently categorised as either Traditional or AIG items. Three outcomes were reported: (i) the items produced using traditional and AIG processes were comparable on seven of eight indicators of multiple-choice item quality; (ii) AIG items can be differentiated from Traditional items by the quality of their distractors, and (iii) the overall predictive accuracy of the four expert medical panellists was 42%. Items generated by AIG methods are, for the most part, equivalent to traditionally developed items from the perspective of expert medical reviewers. While the AIG method produced comparatively fewer plausible

  10. Assessing item fit for unidimensional item response theory models using residuals from estimated item response functions.

    Science.gov (United States)

    Haberman, Shelby J; Sinharay, Sandip; Chon, Kyong Hee

    2013-07-01

    Residual analysis (e.g. Hambleton & Swaminathan, Item response theory: principles and applications, Kluwer Academic, Boston, 1985; Hambleton, Swaminathan, & Rogers, Fundamentals of item response theory, Sage, Newbury Park, 1991) is a popular method to assess fit of item response theory (IRT) models. We suggest a form of residual analysis that may be applied to assess item fit for unidimensional IRT models. The residual analysis consists of a comparison of the maximum-likelihood estimate of the item characteristic curve with an alternative ratio estimate of the item characteristic curve. The large sample distribution of the residual is proved to be standardized normal when the IRT model fits the data. We compare the performance of our suggested residual to the standardized residual of Hambleton et al. (Fundamentals of item response theory, Sage, Newbury Park, 1991) in a detailed simulation study. We then calculate our suggested residuals using data from an operational test. The residuals appear to be useful in assessing the item fit for unidimensional IRT models.

  11. Efficient Algorithms for Segmentation of Item-Set Time Series

    Science.gov (United States)

    Chundi, Parvathi; Rosenkrantz, Daniel J.

    We propose a special type of time series, which we call an item-set time series, to facilitate the temporal analysis of software version histories, email logs, stock market data, etc. In an item-set time series, each observed data value is a set of discrete items. We formalize the concept of an item-set time series and present efficient algorithms for segmenting a given item-set time series. Segmentation of a time series partitions the time series into a sequence of segments where each segment is constructed by combining consecutive time points of the time series. Each segment is associated with an item set that is computed from the item sets of the time points in that segment, using a function which we call a measure function. We then define a concept called the segment difference, which measures the difference between the item set of a segment and the item sets of the time points in that segment. The segment difference values are required to construct an optimal segmentation of the time series. We describe novel and efficient algorithms to compute segment difference values for each of the measure functions described in the paper. We outline a dynamic programming based scheme to construct an optimal segmentation of the given item-set time series. We use the item-set time series segmentation techniques to analyze the temporal content of three different data sets—Enron email, stock market data, and a synthetic data set. The experimental results show that an optimal segmentation of item-set time series data captures much more temporal content than a segmentation constructed based on the number of time points in each segment, without examining the item set data at the time points, and can be used to analyze different types of temporal data.

  12. Three Modeling Applications to Promote Automatic Item Generation for Examinations in Dentistry.

    Science.gov (United States)

    Lai, Hollis; Gierl, Mark J; Byrne, B Ellen; Spielman, Andrew I; Waldschmidt, David M

    2016-03-01

    Test items created for dentistry examinations are often individually written by content experts. This approach to item development is expensive because it requires the time and effort of many content experts but yields relatively few items. The aim of this study was to describe and illustrate how items can be generated using a systematic approach. Automatic item generation (AIG) is an alternative method that allows a small number of content experts to produce large numbers of items by integrating their domain expertise with computer technology. This article describes and illustrates how three modeling approaches to item content-item cloning, cognitive modeling, and image-anchored modeling-can be used to generate large numbers of multiple-choice test items for examinations in dentistry. Test items can be generated by combining the expertise of two content specialists with technology supported by AIG. A total of 5,467 new items were created during this study. From substitution of item content, to modeling appropriate responses based upon a cognitive model of correct responses, to generating items linked to specific graphical findings, AIG has the potential for meeting increasing demands for test items. Further, the methods described in this study can be generalized and applied to many other item types. Future research applications for AIG in dental education are discussed.

  13. More is not Always Better: The Relation between Item Response and Item Response Time in Raven’s Matrices

    Directory of Open Access Journals (Sweden)

    Frank Goldhammer

    2015-03-01

    Full Text Available The role of response time in completing an item can have very different interpretations. Responding more slowly could be positively related to success as the item is answered more carefully. However, the association may be negative if working faster indicates higher ability. The objective of this study was to clarify the validity of each assumption for reasoning items considering the mode of processing. A total of 230 persons completed a computerized version of Raven’s Advanced Progressive Matrices test. Results revealed that response time overall had a negative effect. However, this effect was moderated by items and persons. For easy items and able persons the effect was strongly negative, for difficult items and less able persons it was less negative or even positive. The number of rules involved in a matrix problem proved to explain item difficulty significantly. Most importantly, a positive interaction effect between the number of rules and item response time indicated that the response time effect became less negative with an increasing number of rules. Moreover, exploratory analyses suggested that the error type influenced the response time effect.

  14. Numerosity estimates for attended and unattended items in visual search.

    Science.gov (United States)

    Kelley, Troy D; Cassenti, Daniel N; Marusich, Laura R; Ghirardelli, Thomas G

    2017-07-01

    The goal of this research was to examine memories created for the number of items during a visual search task. Participants performed a visual search task for a target defined by a single feature (Experiment 1A), by a conjunction of features (Experiment 1B), or by a specific spatial configuration of features (Experiment 1C). On some trials following the search task, subjects were asked to recall the total number of items in the previous display. In all search types, participants underestimated the total number of items, but the severity of the underestimation varied depending on the efficiency of the search. In three follow-up studies (Experiments 2A, 2B, and 2C) using the same visual stimuli, the participants' only task was to estimate the number of items on each screen. Participants still underestimated the numerosity of the items, although the degree of underestimation was smaller than in the search tasks and did not depend on the type of visual stimuli. In Experiment 3, participants were asked to recall the number of items in a display only once. Subjects still displayed a tendency to underestimate, indicating that the underestimation effects seen in Experiments 1A-1C were not attributable to knowledge of the estimation task. The degree of underestimation depends on the efficiency of the search task, with more severe underestimation in efficient search tasks. This suggests that the lower attentional demands of very efficient searches leads to less encoding of numerosity of the distractor set.

  15. 48 CFR 852.214-72 - Alternate item(s).

    Science.gov (United States)

    2010-10-01

    ... AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses 852.214-72... 2008) Bids on []* will be given equal consideration along with bids on []** and any such bids received... [].** * Contracting officer will insert an alternate item that is considered acceptable. ** Contracting officer will...

  16. The staging area concept for item control

    International Nuclear Information System (INIS)

    Williams, R.A.

    1984-01-01

    Accounting for special nuclear material contained in fabricated nuclear fuel rod items has been completely automated at the Westinghouse Nuclear Fuel Division facility in Columbia, South Carolina. Experience with the automated system has shown substantial difficulty in maintaining current knowledge of the precise locations of rods pulled out of the ''normal'' processing cycle. This has been resolved by creation of two tightly controlled staging areas for handling and distribution of all ''deviant'' rods by two specially trained expeditors. Thus, coupling automated data collection with centralized expert handling and distribution has created a viable system for control of large numbers of fuel rods in a major fabrication plant

  17. Modelling sequentially scored item responses

    NARCIS (Netherlands)

    Akkermans, W.

    2000-01-01

    The sequential model can be used to describe the variable resulting from a sequential scoring process. In this paper two more item response models are investigated with respect to their suitability for sequential scoring: the partial credit model and the graded response model. The investigation is

  18. Item level diagnostics and model - data fit in item response theory ...

    African Journals Online (AJOL)

    Item response theory (IRT) is a framework for modeling and analyzing item response data. Item-level modeling gives IRT advantages over classical test theory. The fit of an item score pattern to an item response theory (IRT) models is a necessary condition that must be assessed for further use of item and models that best fit ...

  19. Separating relational from item load effects in paired recognition: temporoparietal and middle frontal gyral activity with increased associates, but not items during encoding and retention.

    Science.gov (United States)

    Phillips, Steven; Niki, Kazuhisa

    2002-10-01

    Working memory is affected by items stored and the relations between them. However, separating these factors has been difficult, because increased items usually accompany increased associations/relations. Hence, some have argued, relational effects are reducible to item effects. We overcome this problem by manipulating index length: the fewest number of item positions at which there is a unique item, or tuple of items (if length >1), for every instance in the relational (memory) set. Longer indexes imply greater similarity (number of shared items) between instances and higher load on encoding processes. Subjects were given lists of study pairs and asked to make a recognition judgement. The number of unique items and index length in the three list conditions were: (1) AB, CD: four/one; (2) AB, CD, EF: six/one; and (3) AB, AD, CB: four/two, respectively. Japanese letters were used in Experiments 1 (kanji-ideograms) and 2 (hiragana-phonograms); numbers in Experiment 3; and shapes generated from Fourier descriptors in Experiment 4. Across all materials, right dominant temporoparietal and middle frontal gyral activity was found with increased index length, but not items during study. In Experiment 5, a longer delay was used to isolate retention effects in the absence of visual stimuli. Increased left hemispheric activity was observed in the precuneus, middle frontal gyrus, and superior temporal gyrus with increased index length for the delay period. These results show that relational load is not reducible to item load.

  20. Closed loop two-echelon repairable item systems

    NARCIS (Netherlands)

    Spanjers, L.; van Ommeren, Jan C.W.; Zijm, Willem H.M.

    In this paper we consider closed loop two-echelon repairable item systems with repair facilities both at a number of local service centers (called bases) and at a central location (the depot). The goal of the system is to maintain a number of production facilities (one at each base) in optimal

  1. Closed-loop two-echelon repairable item systems

    NARCIS (Netherlands)

    Spanjers, L.; Zijm, Willem H.M.; van Ommeren, Jan C.W.

    2003-01-01

    In this paper we consider closed loop two-echelon repairable item systems with repair facilities both at a number of local service centers (called bases) and at a central location (the depot). The goal of the system is to maintain a number of production facilities (one at each base) in optimal

  2. Closed loop two-echelon repairable item systems

    NARCIS (Netherlands)

    Spanjers, L.; van Ommeren, Jan C.W.; Zijm, Willem H.M.; Liberopoulos, G.; Papadopoulos, C.T.; Tan, B.; MacGregor Smith, J.; Gershwin, S.B.

    2006-01-01

    In this paper we consider closed loop two-echelon epairable item systems with repair facilities both at a number of local service centers (called bases) and at a central location (the depot). The goal of the system is to maintain a number of production facilities (one at each base) in optimal

  3. Brief Sensation Seeking Scale: Latent structure of 8-item and 4-item versions in Peruvian adolescents.

    Science.gov (United States)

    Merino-Soto, Cesar; Salas Blas, Edwin

    2018-01-01

    This research intended to validate two brief scales of sensations seeking with Peruvian adolescents: the eight item scale (BSSS8; Hoyle, Stephenson, Palmgreen, Lorch, y Donohew, 2002) and the four item scale (BSSS4; Stephenson, Hoyle, Slater, y Palmgreen, 2003). Questionnaires were administered to 618 voluntary participants, with an average age of 13.6 years, from different levels of high school, state and private school in a district in the south of Lima. It analyzed the internal structure of both short versions using three models: a) unidimensional (M1), b) oblique or related dimensions (M2), and c) the bifactor model (M3). Results show that both instruments have a single dimension which best represents the variability of the items; a fact that can be explained both by the complexity of the concept and by the small number of items representing each factor, which is more noticeable in the BSSS4. Reliability is within levels found by previous studies: alpha: .745 = BSSS8 and BSSS4 =. 643; omega coefficient: .747 in BSSS8 and .651 in BSSS4. These are considered suitable for the type of instruments studied. Based on the correlation between the two instruments, it was found that there are satisfactory levels of equivalence between the BSSS8 and BSSS4. However, it is recommended that the BSSS4 is mainly used for research and for the purpose of describing populations.

  4. Non-ignorable missingness item response theory models for choice effects in examinee-selected items.

    Science.gov (United States)

    Liu, Chen-Wei; Wang, Wen-Chung

    2017-11-01

    Examinee-selected item (ESI) design, in which examinees are required to respond to a fixed number of items in a given set, always yields incomplete data (i.e., when only the selected items are answered, data are missing for the others) that are likely non-ignorable in likelihood inference. Standard item response theory (IRT) models become infeasible when ESI data are missing not at random (MNAR). To solve this problem, the authors propose a two-dimensional IRT model that posits one unidimensional IRT model for observed data and another for nominal selection patterns. The two latent variables are assumed to follow a bivariate normal distribution. In this study, the mirt freeware package was adopted to estimate parameters. The authors conduct an experiment to demonstrate that ESI data are often non-ignorable and to determine how to apply the new model to the data collected. Two follow-up simulation studies are conducted to assess the parameter recovery of the new model and the consequences for parameter estimation of ignoring MNAR data. The results of the two simulation studies indicate good parameter recovery of the new model and poor parameter recovery when non-ignorable missing data were mistakenly treated as ignorable. © 2017 The British Psychological Society.

  5. Quantum Partial Searching Algorithm of a Database with Several Target Items

    International Nuclear Information System (INIS)

    Pu-Cha, Zhong; Wan-Su, Bao; Yun, Wei

    2009-01-01

    Choi and Korepin [Quantum Information Processing 6(2007)243] presented a quantum partial search algorithm of a database with several target items which can find a target block quickly when each target block contains the same number of target items. Actually, the number of target items in each target block is arbitrary. Aiming at this case, we give a condition to guarantee performance of the partial search algorithm to be performed and the number of queries to oracle of the algorithm to be minimized. In addition, by further numerical computing we come to the conclusion that the more uniform the distribution of target items, the smaller the number of queries

  6. Psychometric Consequences of Subpopulation Item Parameter Drift

    Science.gov (United States)

    Huggins-Manley, Anne Corinne

    2017-01-01

    This study defines subpopulation item parameter drift (SIPD) as a change in item parameters over time that is dependent on subpopulations of examinees, and hypothesizes that the presence of SIPD in anchor items is associated with bias and/or lack of invariance in three psychometric outcomes. Results show that SIPD in anchor items is associated…

  7. Generalizability theory and item response theory

    NARCIS (Netherlands)

    Glas, Cornelis A.W.; Eggen, T.J.H.M.; Veldkamp, B.P.

    2012-01-01

    Item response theory is usually applied to items with a selected-response format, such as multiple choice items, whereas generalizability theory is usually applied to constructed-response tasks assessed by raters. However, in many situations, raters may use rating scales consisting of items with a

  8. Developing an item bank to measure the coping strategies of people with hereditary retinal diseases.

    Science.gov (United States)

    Prem Senthil, Mallika; Khadka, Jyoti; De Roach, John; Lamey, Tina; McLaren, Terri; Campbell, Isabella; Fenwick, Eva K; Lamoureux, Ecosse L; Pesudovs, Konrad

    2018-05-05

    Our understanding of the coping strategies used by people with visual impairment to manage stress related to visual loss is limited. This study aims to develop a sophisticated coping instrument in the form of an item bank implemented via Computerised adaptive testing (CAT) for hereditary retinal diseases. Items on coping were extracted from qualitative interviews with patients which were supplemented by items from a literature review. A systematic multi-stage process of item refinement was carried out followed by expert panel discussion and cognitive interviews. The final coping item bank had 30 items. Rasch analysis was used to assess the psychometric properties. A CAT simulation was carried out to estimate an average number of items required to gain precise measurement of hereditary retinal disease-related coping. One hundred eighty-nine participants answered the coping item bank (median age = 58 years). The coping scale demonstrated good precision and targeting. The standardised residual loadings for items revealed six items grouped together. Removal of the six items reduced the precision of the main coping scale and worsened the variance explained by the measure. Therefore, the six items were retained within the main scale. Our CAT simulation indicated that, on average, less than 10 items are required to gain a precise measurement of coping. This is the first study to develop a psychometrically robust coping instrument for hereditary retinal diseases. CAT simulation indicated that on an average, only four and nine items were required to gain measurement at moderate and high precision, respectively.

  9. Generalizability theory and item response theory

    OpenAIRE

    Glas, Cornelis A.W.; Eggen, T.J.H.M.; Veldkamp, B.P.

    2012-01-01

    Item response theory is usually applied to items with a selected-response format, such as multiple choice items, whereas generalizability theory is usually applied to constructed-response tasks assessed by raters. However, in many situations, raters may use rating scales consisting of items with a selected-response format. This chapter presents a short overview of how item response theory and generalizability theory were integrated to model such assessments. Further, the precision of the esti...

  10. Teoria da Resposta ao Item Teoria de la respuesta al item Item response theory

    Directory of Open Access Journals (Sweden)

    Eutalia Aparecida Candido de Araujo

    2009-12-01

    Full Text Available A preocupação com medidas de traços psicológicos é antiga, sendo que muitos estudos e propostas de métodos foram desenvolvidos no sentido de alcançar este objetivo. Entre os trabalhos propostos, destaca-se a Teoria da Resposta ao Item (TRI que, a princípio, veio completar limitações da Teoria Clássica de Medidas, empregada em larga escala até hoje na medida de traços psicológicos. O ponto principal da TRI é que ela leva em consideração o item particularmente, sem relevar os escores totais; portanto, as conclusões não dependem apenas do teste ou questionário, mas de cada item que o compõe. Este artigo propõe-se a apresentar esta Teoria que revolucionou a teoria de medidas.La preocupación con las medidas de los rasgos psicológicos es antigua y muchos estudios y propuestas de métodos fueron desarrollados para lograr este objetivo. Entre estas propuestas de trabajo se incluye la Teoría de la Respuesta al Ítem (TRI que, en principio, vino a completar las limitaciones de la Teoría Clásica de los Tests, ampliamente utilizada hasta hoy en la medida de los rasgos psicológicos. El punto principal de la TRI es que se tiene en cuenta el punto concreto, sin relevar las puntuaciones totales; por lo tanto, los resultados no sólo dependen de la prueba o cuestionario, sino que de cada ítem que lo compone. En este artículo se propone presentar la Teoría que revolucionó la teoría de medidas.The concern with measures of psychological traits is old and many studies and proposals of methods were developed to achieve this goal. Among these proposed methods highlights the Item Response Theory (IRT that, in principle, came to complete limitations of the Classical Test Theory, which is widely used until nowadays in the measurement of psychological traits. The main point of IRT is that it takes into account the item in particular, not relieving the total scores; therefore, the findings do not only depend on the test or questionnaire

  11. Sharing the cost of redundant items

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moulin, Hervé

    2014-01-01

    We ask how to share the cost of finitely many public goods (items) among users with different needs: some smaller subsets of items are enough to serve the needs of each user, yet the cost of all items must be covered, even if this entails inefficiently paying for redundant items. Typical examples...... are network connectivity problems when an existing (possibly inefficient) network must be maintained. We axiomatize a family cost ratios based on simple liability indices, one for each agent and for each item, measuring the relative worth of this item across agents, and generating cost allocation rules...... additive in costs....

  12. A Bifactor Multidimensional Item Response Theory Model for Differential Item Functioning Analysis on Testlet-Based Items

    Science.gov (United States)

    Fukuhara, Hirotaka; Kamata, Akihito

    2011-01-01

    A differential item functioning (DIF) detection method for testlet-based data was proposed and evaluated in this study. The proposed DIF model is an extension of a bifactor multidimensional item response theory (MIRT) model for testlets. Unlike traditional item response theory (IRT) DIF models, the proposed model takes testlet effects into…

  13. Emergency Power For Critical Items

    Science.gov (United States)

    Young, William R.

    2009-07-01

    Natural disasters, such as hurricanes, floods, tornados, and tsunami, are becoming a greater problem as climate change impacts our environment. Disasters, whether natural or man made, destroy lives, homes, businesses and the natural environment. Such disasters can happen with little or no warning, leaving hundreds or even thousands of people without medical services, potable water, sanitation, communications and electrical services for up to several weeks. In our modern world, the need for electricity has become a necessity. Modern building codes and new disaster resistant building practices are reducing the damage to homes and businesses. Emergency gasoline and diesel generators are becoming common place for power outages. Generators need fuel, which may not be available after a disaster, but Photovoltaic (solar-electric) systems supply electricity without petroleum fuel as they are powered by the sun. Photovoltaic (PV) systems can provide electrical power for a home or business. PV systems can operate as utility interactive or stand-alone with battery backup. Determining your critical load items and sizing the photovoltaic system for those critical items, guarantees their operation in a disaster.

  14. Hupa Numbers.

    Science.gov (United States)

    Bennett, Ruth, Ed.; And Others

    An introduction to the Hupa number system is provided in this workbook, one in a series of numerous materials developed to promote the use of the Hupa language. The book is written in English with Hupa terms used only for the names of numbers. The opening pages present the numbers from 1-10, giving the numeral, the Hupa word, the English word, and…

  15. Triangular Numbers

    Indian Academy of Sciences (India)

    Admin

    Triangular number, figurate num- ber, rangoli, Brahmagupta–Pell equation, Jacobi triple product identity. Figure 1. The first four triangular numbers. Left: Anuradha S Garge completed her PhD from. Pune University in 2008 under the supervision of Prof. S A Katre. Her research interests include K-theory and number theory.

  16. Proth Numbers

    Directory of Open Access Journals (Sweden)

    Schwarzweller Christoph

    2015-02-01

    Full Text Available In this article we introduce Proth numbers and prove two theorems on such numbers being prime [3]. We also give revised versions of Pocklington’s theorem and of the Legendre symbol. Finally, we prove Pepin’s theorem and that the fifth Fermat number is not prime.

  17. Item response theory analysis of the mechanics baseline test

    Science.gov (United States)

    Cardamone, Caroline N.; Abbott, Jonathan E.; Rayyan, Saif; Seaton, Daniel T.; Pawl, Andrew; Pritchard, David E.

    2012-02-01

    Item response theory is useful in both the development and evaluation of assessments and in computing standardized measures of student performance. In item response theory, individual parameters (difficulty, discrimination) for each item or question are fit by item response models. These parameters provide a means for evaluating a test and offer a better measure of student skill than a raw test score, because each skill calculation considers not only the number of questions answered correctly, but the individual properties of all questions answered. Here, we present the results from an analysis of the Mechanics Baseline Test given at MIT during 2005-2010. Using the item parameters, we identify questions on the Mechanics Baseline Test that are not effective in discriminating between MIT students of different abilities. We show that a limited subset of the highest quality questions on the Mechanics Baseline Test returns accurate measures of student skill. We compare student skills as determined by item response theory to the more traditional measurement of the raw score and show that a comparable measure of learning gain can be computed.

  18. Sagan numbers

    OpenAIRE

    Mendonça, J. Ricardo G.

    2012-01-01

    We define a new class of numbers based on the first occurrence of certain patterns of zeros and ones in the expansion of irracional numbers in a given basis and call them Sagan numbers, since they were first mentioned, in a special case, by the North-american astronomer Carl E. Sagan in his science-fiction novel "Contact." Sagan numbers hold connections with a wealth of mathematical ideas. We describe some properties of the newly defined numbers and indicate directions for further amusement.

  19. A Balance Sheet for Educational Item Banking.

    Science.gov (United States)

    Hiscox, Michael D.

    Educational item banking presents observers with a considerable paradox. The development of test items from scratch is viewed as wasteful, a luxury in times of declining resources. On the other hand, item banking has failed to become a mature technology despite large amounts of money and the efforts of talented professionals. The question of which…

  20. 76 FR 60474 - Commercial Item Handbook

    Science.gov (United States)

    2011-09-29

    ... DEPARTMENT OF DEFENSE Defense Acquisition Regulations System Commercial Item Handbook AGENCY.... SUMMARY: DoD has updated its Commercial Item Handbook. The purpose of the Handbook is to help acquisition personnel develop sound business strategies for procuring commercial items. DoD is seeking industry input on...

  1. Towards an authoring system for item construction

    NARCIS (Netherlands)

    Rikers, Jos H.A.N.

    1988-01-01

    The process of writing test items is analyzed, and a blueprint is presented for an authoring system for test item writing to reduce invalidity and to structure the process of item writing. The developmental methodology is introduced, and the first steps in the process are reported. A historical

  2. Obtaining a Proportional Allocation by Deleting Items

    NARCIS (Netherlands)

    Dorn, B.; de Haan, R.; Schlotter, I.; Röthe, J.

    2017-01-01

    We consider the following control problem on fair allocation of indivisible goods. Given a set I of items and a set of agents, each having strict linear preference over the items, we ask for a minimum subset of the items whose deletion guarantees the existence of a proportional allocation in the

  3. Item Analysis in Introductory Economics Testing.

    Science.gov (United States)

    Tinari, Frank D.

    1979-01-01

    Computerized analysis of multiple choice test items is explained. Examples of item analysis applications in the introductory economics course are discussed with respect to three objectives: to evaluate learning; to improve test items; and to help improve classroom instruction. Problems, costs and benefits of the procedures are identified. (JMD)

  4. Sales Models For Many Items Using Attribute Data

    NARCIS (Netherlands)

    J.E.M. van Nierop; D. Fok (Dennis); Ph.H.B.F. Franses (Philip Hans)

    2002-01-01

    textabstractSales models are mainly used to analyze markets with a fairly small number of items, obtained after aggregating to the brand level. In practice one may require analyses at a more disaggregate level. For example, brand managers may be interested in a comparison across product

  5. The variety, popularity and nutritional quality of tuck shop items ...

    African Journals Online (AJOL)

    Method: A cross-sectional tuck shop survey. Nutritional analyses were conducted using the ... Results: Savoury pies were the most popular lunch item for all learners for both breaks (n = 5, 45%, and n = 3, 27.3%), selling the most number of units (43) per day at eight schools (72.7%). Iced popsicles were sold at almost every ...

  6. Detection of differential item functioning using Lagrange multiplier tests

    NARCIS (Netherlands)

    Glas, Cornelis A.W.

    1998-01-01

    Abstract: In the present paper it is shown that differential item functioning can be evaluated using the Lagrange multiplier test or Rao’s efficient score test. The test is presented in the framework of a number of IRT models such as the Rasch model, the OPLM, the 2-parameter logistic model, the

  7. New technologies for item monitoring

    International Nuclear Information System (INIS)

    Abbott, J.A.; Waddoups, I.G.

    1993-12-01

    This report responds to the Department of Energy's request that Sandia National Laboratories compare existing technologies against several advanced technologies as they apply to DOE needs to monitor the movement of material, weapons, or personnel for safety and security programs. The authors describe several material control systems, discuss their technologies, suggest possible applications, discuss assets and limitations, and project costs for each system. The following systems are described: WATCH system (Wireless Alarm Transmission of Container Handling); Tag system (an electrostatic proximity sensor); PANTRAK system (Personnel And Material Tracking); VRIS (Vault Remote Inventory System); VSIS (Vault Safety and Inventory System); AIMS (Authenticated Item Monitoring System); EIVS (Experimental Inventory Verification System); Metrox system (canister monitoring system); TCATS (Target Cueing And Tracking System); LGVSS (Light Grid Vault Surveillance System); CSS (Container Safeguards System); SAMMS (Security Alarm and Material Monitoring System); FOIDS (Fiber Optic Intelligence ampersand Detection System); GRADS (Graded Radiation Detection System); and PINPAL (Physical Inventory Pallet)

  8. New technologies for item monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, J.A. [EG & G Energy Measurements, Albuquerque, NM (United States); Waddoups, I.G. [Sandia National Labs., Albuquerque, NM (United States)

    1993-12-01

    This report responds to the Department of Energy`s request that Sandia National Laboratories compare existing technologies against several advanced technologies as they apply to DOE needs to monitor the movement of material, weapons, or personnel for safety and security programs. The authors describe several material control systems, discuss their technologies, suggest possible applications, discuss assets and limitations, and project costs for each system. The following systems are described: WATCH system (Wireless Alarm Transmission of Container Handling); Tag system (an electrostatic proximity sensor); PANTRAK system (Personnel And Material Tracking); VRIS (Vault Remote Inventory System); VSIS (Vault Safety and Inventory System); AIMS (Authenticated Item Monitoring System); EIVS (Experimental Inventory Verification System); Metrox system (canister monitoring system); TCATS (Target Cueing And Tracking System); LGVSS (Light Grid Vault Surveillance System); CSS (Container Safeguards System); SAMMS (Security Alarm and Material Monitoring System); FOIDS (Fiber Optic Intelligence & Detection System); GRADS (Graded Radiation Detection System); and PINPAL (Physical Inventory Pallet).

  9. Eulerian numbers

    CERN Document Server

    Petersen, T Kyle

    2015-01-01

    This text presents the Eulerian numbers in the context of modern enumerative, algebraic, and geometric combinatorics. The book first studies Eulerian numbers from a purely combinatorial point of view, then embarks on a tour of how these numbers arise in the study of hyperplane arrangements, polytopes, and simplicial complexes. Some topics include a thorough discussion of gamma-nonnegativity and real-rootedness for Eulerian polynomials, as well as the weak order and the shard intersection order of the symmetric group. The book also includes a parallel story of Catalan combinatorics, wherein the Eulerian numbers are replaced with Narayana numbers. Again there is a progression from combinatorics to geometry, including discussion of the associahedron and the lattice of noncrossing partitions. The final chapters discuss how both the Eulerian and Narayana numbers have analogues in any finite Coxeter group, with many of the same enumerative and geometric properties. There are four supplemental chapters throughout, ...

  10. Approximation Preserving Reductions among Item Pricing Problems

    Science.gov (United States)

    Hamane, Ryoso; Itoh, Toshiya; Tomita, Kouhei

    When a store sells items to customers, the store wishes to determine the prices of the items to maximize its profit. Intuitively, if the store sells the items with low (resp. high) prices, the customers buy more (resp. less) items, which provides less profit to the store. So it would be hard for the store to decide the prices of items. Assume that the store has a set V of n items and there is a set E of m customers who wish to buy those items, and also assume that each item i ∈ V has the production cost di and each customer ej ∈ E has the valuation vj on the bundle ej ⊆ V of items. When the store sells an item i ∈ V at the price ri, the profit for the item i is pi = ri - di. The goal of the store is to decide the price of each item to maximize its total profit. We refer to this maximization problem as the item pricing problem. In most of the previous works, the item pricing problem was considered under the assumption that pi ≥ 0 for each i ∈ V, however, Balcan, et al. [In Proc. of WINE, LNCS 4858, 2007] introduced the notion of “loss-leader, ” and showed that the seller can get more total profit in the case that pi < 0 is allowed than in the case that pi < 0 is not allowed. In this paper, we derive approximation preserving reductions among several item pricing problems and show that all of them have algorithms with good approximation ratio.

  11. Item Modeling Concept Based on Multimedia Authoring

    Directory of Open Access Journals (Sweden)

    Janez Stergar

    2008-09-01

    Full Text Available In this paper a modern item design framework for computer based assessment based on Flash authoring environment will be introduced. Question design will be discussed as well as the multimedia authoring environment used for item modeling emphasized. Item type templates are a structured means of collecting and storing item information that can be used to improve the efficiency and security of the innovative item design process. Templates can modernize the item design, enhance and speed up the development process. Along with content creation, multimedia has vast potential for use in innovative testing. The introduced item design template is based on taxonomy of innovative items which have great potential for expanding the content areas and construct coverage of an assessment. The presented item design approach is based on GUI's – one for question design based on implemented item design templates and one for user interaction tracking/retrieval. The concept of user interfaces based on Flash technology will be discussed as well as implementation of the innovative approach of the item design forms with multimedia authoring. Also an innovative method for user interaction storage/retrieval based on PHP extending Flash capabilities in the proposed framework will be introduced.

  12. Losing Items in the Psychogeriatric Nursing Home

    Directory of Open Access Journals (Sweden)

    J. van Hoof PhD

    2016-09-01

    Full Text Available Introduction: Losing items is a time-consuming occurrence in nursing homes that is ill described. An explorative study was conducted to investigate which items got lost by nursing home residents, and how this affects the residents and family caregivers. Method: Semi-structured interviews and card sorting tasks were conducted with 12 residents with early-stage dementia and 12 family caregivers. Thematic analysis was applied to the outcomes of the sessions. Results: The participants stated that numerous personal items and assistive devices get lost in the nursing home environment, which had various emotional, practical, and financial implications. Significant amounts of time are spent on trying to find items, varying from 1 hr up to a couple of weeks. Numerous potential solutions were identified by the interviewees. Discussion: Losing items often goes together with limitations to the participation of residents. Many family caregivers are reluctant to replace lost items, as these items may get lost again.

  13. Transfinite Numbers

    Indian Academy of Sciences (India)

    Transfinite Numbers. What is Infinity? S M Srivastava. In a series of revolutionary articles written during the last quarter of the nineteenth century, the great Ger- man mathematician Georg Cantor removed the age-old mistrust of infinity and created an exceptionally beau- tiful and useful theory of transfinite numbers. This is.

  14. Applying automatic item generation to create cohesive physics testlets

    Science.gov (United States)

    Mindyarto, B. N.; Nugroho, S. E.; Linuwih, S.

    2018-03-01

    Computer-based testing has created the demand for large numbers of items. This paper discusses the production of cohesive physics testlets using an automatic item generation concepts and procedures. The testlets were composed by restructuring physics problems to reveal deeper understanding of the underlying physical concepts by inserting a qualitative question and its scientific reasoning question. A template-based testlet generator was used to generate the testlet variants. Using this methodology, 1248 testlet variants were effectively generated from 25 testlet templates. Some issues related to the effective application of the generated physics testlets in practical assessments were discussed.

  15. Developing a short version of the Toronto Structured Interview for Alexithymia using item response theory.

    Science.gov (United States)

    Sekely, Angela; Taylor, Graeme J; Bagby, R Michael

    2018-03-17

    The Toronto Structured Interview for Alexithymia (TSIA) was developed to provide a structured interview method for assessing alexithymia. One drawback of this instrument is the amount of time it takes to administer and score. The current study used item response theory (IRT) methods to analyze data from a large heterogeneous multi-language sample (N = 842) to investigate whether a subset of items could be selected to create a short version of the instrument. Samejima's (1969) graded response model was used to fit the item responses. Items providing maximum information were retained in the short model, resulting in the elimination of 12-items from the original 24-items. Despite the 50% reduction in the number of items, 65.22% of the information was retained. Further studies are needed to validate the short version. A short version of the TSIA is potentially of practical value to clinicians and researchers with time constraints. Copyright © 2018. Published by Elsevier B.V.

  16. Using Differential Item Functioning Procedures to Explore Sources of Item Difficulty and Group Performance Characteristics.

    Science.gov (United States)

    Scheuneman, Janice Dowd; Gerritz, Kalle

    1990-01-01

    Differential item functioning (DIF) methodology for revealing sources of item difficulty and performance characteristics of different groups was explored. A total of 150 Scholastic Aptitude Test items and 132 Graduate Record Examination general test items were analyzed. DIF was evaluated for males and females and Blacks and Whites. (SLD)

  17. Instructional Topics in Educational Measurement (ITEMS) Module: Using Automated Processes to Generate Test Items

    Science.gov (United States)

    Gierl, Mark J.; Lai, Hollis

    2013-01-01

    Changes to the design and development of our educational assessments are resulting in the unprecedented demand for a large and continuous supply of content-specific test items. One way to address this growing demand is with automatic item generation (AIG). AIG is the process of using item models to generate test items with the aid of computer…

  18. Immunity to VHS virus in rainbow trout

    DEFF Research Database (Denmark)

    Lorenzen, Niels; Olesen, Niels Jørgen; Koch, C.

    1999-01-01

    Viral hemorrhagic septicemia virus (VHSV) is the rhabdovirus that causes most disease problems in farmed rainbow trout in Europe. Survivors of infection are usually immune to reinfection but as with other fish viruses, development of a modern recombinant vaccine has been complicated by the limited...... knowledge of the immune mechanisms and antigens involved in induction of immunity. Neutralizing and protective monoclonal antibodies recognize the envelope glycoprotein (G protein) which is the only viral protein known to be present on the surface of the virus particle. Immunoblotting analyses...... with monoclonal antibodies as well as with sera from immunized trout have indicated that protein conformation plays an important role in neutralization epitopes. The virus neutralizing activity often found in sera from convalescent trout is highly dependent on a poorly defined complementing activity in normal...

  19. Chocolate Numbers

    OpenAIRE

    Ji, Caleb; Khovanova, Tanya; Park, Robin; Song, Angela

    2015-01-01

    In this paper, we consider a game played on a rectangular $m \\times n$ gridded chocolate bar. Each move, a player breaks the bar along a grid line. Each move after that consists of taking any piece of chocolate and breaking it again along existing grid lines, until just $mn$ individual squares remain. This paper enumerates the number of ways to break an $m \\times n$ bar, which we call chocolate numbers, and introduces four new sequences related to these numbers. Using various techniques, we p...

  20. Number theory

    CERN Document Server

    Andrews, George E

    1994-01-01

    Although mathematics majors are usually conversant with number theory by the time they have completed a course in abstract algebra, other undergraduates, especially those in education and the liberal arts, often need a more basic introduction to the topic.In this book the author solves the problem of maintaining the interest of students at both levels by offering a combinatorial approach to elementary number theory. In studying number theory from such a perspective, mathematics majors are spared repetition and provided with new insights, while other students benefit from the consequent simpl

  1. Dependability of technical items: Problems of standardization

    Science.gov (United States)

    Fedotova, G. A.; Voropai, N. I.; Kovalev, G. F.

    2016-12-01

    This paper is concerned with problems blown up in the development of a new version of the Interstate Standard GOST 27.002 "Industrial product dependability. Terms and definitions". This Standard covers a wide range of technical items and is used in numerous regulations, specifications, standard and technical documentation. A currently available State Standard GOST 27.002-89 was introduced in 1990. Its development involved a participation of scientists and experts from different technical areas, its draft was debated in different audiences and constantly refined, so it was a high quality document. However, after 25 years of its application it's become necessary to develop a new version of the Standard that would reflect the current understanding of industrial dependability, accounting for the changes taking place in Russia in the production, management and development of various technical systems and facilities. The development of a new version of the Standard makes it possible to generalize on a terminological level the knowledge and experience in the area of reliability of technical items, accumulated over a quarter of the century in different industries and reliability research schools, to account for domestic and foreign experience of standardization. Working on the new version of the Standard, we have faced a number of issues and problems on harmonization with the International Standard IEC 60500-192, caused first of all by different approaches to the use of terms and differences in the mentalities of experts from different countries. The paper focuses on the problems related to the chapter "Maintenance, restoration and repair", which caused difficulties for the developers to harmonize term definitions both with experts and the International Standard, which is mainly related to differences between the Russian concept and practice of maintenance and repair and foreign ones.

  2. PENGEMBANGAN TES BERPIKIR KRITIS DENGAN PENDEKATAN ITEM RESPONSE THEORY

    Directory of Open Access Journals (Sweden)

    Fajrianthi Fajrianthi

    2016-06-01

    Assumption, Deduction, Interpretation dan Evaluation of arguments. 1453 respondents from Surabaya, Gresik, Tuban, Bojonegoro and Rembang were used for trailing the test. The dichotomous data were analized using the Item Response Theory with two parameter logistic model using statistical program Mplus ver. 6.11. Several assumptions were tested prior the IRT analysis; the test of unidimensionality, local independency and Item Characteristic Curve (ICC. Amongst 68 items only 15 items had good discrimination parameter. Difficulty item level ranged from – 4.95 to 2.448. The study was limited in producing high number of qualified items due to its failure in finding subject matter experts in critical thinking area and inadequate choice in scoring method. Keywords: test development, critical thinking, Item response theory

  3. Validity and Reliability of the 8-Item Work Limitations Questionnaire.

    Science.gov (United States)

    Walker, Timothy J; Tullar, Jessica M; Diamond, Pamela M; Kohl, Harold W; Amick, Benjamin C

    2017-12-01

    Purpose To evaluate factorial validity, scale reliability, test-retest reliability, convergent validity, and discriminant validity of the 8-item Work Limitations Questionnaire (WLQ) among employees from a public university system. Methods A secondary analysis using de-identified data from employees who completed an annual Health Assessment between the years 2009-2015 tested research aims. Confirmatory factor analysis (CFA) (n = 10,165) tested the latent structure of the 8-item WLQ. Scale reliability was determined using a CFA-based approach while test-retest reliability was determined using the intraclass correlation coefficient. Convergent/discriminant validity was tested by evaluating relations between the 8-item WLQ with health/performance variables for convergent validity (health-related work performance, number of chronic conditions, and general health) and demographic variables for discriminant validity (gender and institution type). Results A 1-factor model with three correlated residuals demonstrated excellent model fit (CFI = 0.99, TLI = 0.99, RMSEA = 0.03, and SRMR = 0.01). The scale reliability was acceptable (0.69, 95% CI 0.68-0.70) and the test-retest reliability was very good (ICC = 0.78). Low-to-moderate associations were observed between the 8-item WLQ and the health/performance variables while weak associations were observed between the demographic variables. Conclusions The 8-item WLQ demonstrated sufficient reliability and validity among employees from a public university system. Results suggest the 8-item WLQ is a usable alternative for studies when the more comprehensive 25-item WLQ is not available.

  4. Nice numbers

    CERN Document Server

    Barnes, John

    2016-01-01

    In this intriguing book, John Barnes takes us on a journey through aspects of numbers much as he took us on a geometrical journey in Gems of Geometry. Similarly originating from a series of lectures for adult students at Reading and Oxford University, this book touches a variety of amusing and fascinating topics regarding numbers and their uses both ancient and modern. The author intrigues and challenges his audience with both fundamental number topics such as prime numbers and cryptography, and themes of daily needs and pleasures such as counting one's assets, keeping track of time, and enjoying music. Puzzles and exercises at the end of each lecture offer additional inspiration, and numerous illustrations accompany the reader. Furthermore, a number of appendices provides in-depth insights into diverse topics such as Pascal’s triangle, the Rubik cube, Mersenne’s curious keyboards, and many others. A theme running through is the thought of what is our favourite number. Written in an engaging and witty sty...

  5. Using Automated Processes to Generate Test Items And Their Associated Solutions and Rationales to Support Formative Feedback

    Directory of Open Access Journals (Sweden)

    Mark Gierl

    2015-08-01

    Full Text Available Automatic item generation is the process of using item models to produce assessment tasks using computer technology. An item model is similar to a template that highlights the elements in the task that must be manipulated to produce new items. The purpose of our study is to describe an innovative method for generating large numbers of diverse and heterogeneous items along with their solutions and associated rationales to support formative feedback. We demonstrate the method by generating items in two diverse content areas, mathematics and nonverbal reasoning

  6. [Instrument to measure adherence in hypertensive patients: contribution of Item Response Theory].

    Science.gov (United States)

    Rodrigues, Malvina Thaís Pacheco; Moreira, Thereza Maria Magalhaes; Vasconcelos, Alexandre Meira de; Andrade, Dalton Francisco de; Silva, Daniele Braz da; Barbetta, Pedro Alberto

    2013-06-01

    To analyze, by means of "Item Response Theory", an instrument to measure adherence to t treatment for hypertension. Analytical study with 406 hypertensive patients with associated complications seen in primary care in Fortaleza, CE, Northeastern Brazil, 2011 using "Item Response Theory". The stages were: dimensionality test, calibrating the items, processing data and creating a scale, analyzed using the gradual response model. A study of the dimensionality of the instrument was conducted by analyzing the polychoric correlation matrix and factor analysis of complete information. Multilog software was used to calibrate items and estimate the scores. Items relating to drug therapy are the most directly related to adherence while those relating to drug-free therapy need to be reworked because they have less psychometric information and low discrimination. The independence of items, the small number of levels in the scale and low explained variance in the adjustment of the models show the main weaknesses of the instrument analyzed. The "Item Response Theory" proved to be a relevant analysis technique because it evaluated respondents for adherence to treatment for hypertension, the level of difficulty of the items and their ability to discriminate between individuals with different levels of adherence, which generates a greater amount of information. The instrument analyzed is limited in measuring adherence to hypertension treatment, by analyzing the "Item Response Theory" of the item, and needs adjustment. The proper formulation of the items is important in order to accurately measure the desired latent trait.

  7. Number names and number understanding

    DEFF Research Database (Denmark)

    Ejersbo, Lisser Rye; Misfeldt, Morten

    2014-01-01

    This paper concerns the results from the first year of a three-year research project involving the relationship between Danish number names and their corresponding digits in the canonical base 10 system. The project aims to develop a system to help the students’ understanding of the base 10 syste...... the Danish number names are more complicated than in other languages. Keywords: A research project in grade 0 and 1th in a Danish school, Base-10 system, two-digit number names, semiotic, cognitive perspectives....

  8. CERN Running Club – Sale of Items

    CERN Multimedia

    CERN Running club

    2018-01-01

    The CERN Running Club is organising a sale of items  on 26 June from 11:30 – 13:00 in the entry area of Restaurant 2 (504 R-202). The items for sale are souvenir prizes of past Relay Races and comprise: Backpacks, thermos, towels, gloves & caps, lamps, long sleeve winter shirts and windproof vest. All items will be sold at 5 CHF.

  9. Funny Numbers

    Directory of Open Access Journals (Sweden)

    Theodore M. Porter

    2012-12-01

    Full Text Available The struggle over cure rate measures in nineteenth-century asylums provides an exemplary instance of how, when used for official assessments of institutions, these numbers become sites of contestation. The evasion of goals and corruption of measures tends to make these numbers “funny” in the sense of becoming dis-honest, while the mismatch between boring, technical appearances and cunning backstage manipulations supplies dark humor. The dangers are evident in recent efforts to decentralize the functions of governments and corporations using incen-tives based on quantified targets.

  10. Transcendental numbers

    CERN Document Server

    Murty, M Ram

    2014-01-01

    This book provides an introduction to the topic of transcendental numbers for upper-level undergraduate and graduate students. The text is constructed to support a full course on the subject, including descriptions of both relevant theorems and their applications. While the first part of the book focuses on introducing key concepts, the second part presents more complex material, including applications of Baker’s theorem, Schanuel’s conjecture, and Schneider’s theorem. These later chapters may be of interest to researchers interested in examining the relationship between transcendence and L-functions. Readers of this text should possess basic knowledge of complex analysis and elementary algebraic number theory.

  11. Transfinite Numbers

    Indian Academy of Sciences (India)

    this is a characteristic difference between finite and infinite sets and created an immensely useful branch of mathematics based on this idea which had a great impact on the whole of mathe- matics. For example, the question of what is a number (finite or infinite) is almost a philosophical one. However Cantor's work turned it ...

  12. Human resource management in the delivery of postal items

    Directory of Open Access Journals (Sweden)

    Kujačić Momčilo D.

    2015-01-01

    Full Text Available Delivery of postal items is the last phase in the postal conveyance process. This phase involved up to 57% in total costs of postal items conveyance. In order to reduce the costs of delivery phase, postal organizations apply different methods and techniques. Legal and technological regulations, various restrictions regarding the selection and deployment of employees influence the choice of appropriate methods. Also, the principle of availability of the universal postal service is an essential factor in defining the optimal model. In this paper, the model for assessing and planning of the number of employees in the delivery service observed postal operator has been proposed, with respect to the principles of productivity and accessibility constraints of the universal postal service. This paper will analyze the impact of daily fluctuations in the number of full-time employees and the possibility of hiring a part-time workers in the days with increased traffic volume in the delivery of items, when usually the items from large customers are delivered.

  13. Item analysis of the Spanish version of the Boston Naming Test with a Spanish speaking adult population from Colombia.

    Science.gov (United States)

    Kim, Stella H; Strutt, Adriana M; Olabarrieta-Landa, Laiene; Lequerica, Anthony H; Rivera, Diego; De Los Reyes Aragon, Carlos Jose; Utria, Oscar; Arango-Lasprilla, Juan Carlos

    2018-02-23

    The Boston Naming Test (BNT) is a widely used measure of confrontation naming ability that has been criticized for its questionable construct validity for non-English speakers. This study investigated item difficulty and construct validity of the Spanish version of the BNT to assess cultural and linguistic impact on performance. Subjects were 1298 healthy Spanish speaking adults from Colombia. They were administered the 60- and 15-item Spanish version of the BNT. A Rasch analysis was computed to assess dimensionality, item hierarchy, targeting, reliability, and item fit. Both versions of the BNT satisfied requirements for unidimensionality. Although internal consistency was excellent for the 60-item BNT, order of difficulty did not increase consistently with item number and there were a number of items that did not fit the Rasch model. For the 15-item BNT, a total of 5 items changed position on the item hierarchy with 7 poor fitting items. Internal consistency was acceptable. Construct validity of the BNT remains a concern when it is administered to non-English speaking populations. Similar to previous findings, the order of item presentation did not correspond with increasing item difficulty, and both versions were inadequate at assessing high naming ability.

  14. Optimizing the Use of Response Times for Item Selection in Computerized Adaptive Testing

    Science.gov (United States)

    Choe, Edison M.; Kern, Justin L.; Chang, Hua-Hua

    2018-01-01

    Despite common operationalization, measurement efficiency of computerized adaptive testing should not only be assessed in terms of the number of items administered but also the time it takes to complete the test. To this end, a recent study introduced a novel item selection criterion that maximizes Fisher information per unit of expected response…

  15. Beyond the Shadow of a Trait: Understanding Discounting through Item-Level Analysis of Personality Scales

    Science.gov (United States)

    Charlton, Shawn R.; Gossett, Bradley D.; Charlton, Veda A.

    2011-01-01

    Temporal discounting, the loss in perceived value associated with delayed outcomes, correlates with a number of personality measures, suggesting that an item-level analysis of trait measures might provide a more detailed understanding of discounting. The current report details two studies that investigate the utility of such an item-level…

  16. Exploring differential item functioning in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC

    Directory of Open Access Journals (Sweden)

    Pollard Beth

    2012-12-01

    Full Text Available Abstract Background The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC is a widely used patient reported outcome in osteoarthritis. An important, but frequently overlooked, aspect of validating health outcome measures is to establish if items exhibit differential item functioning (DIF. That is, if respondents have the same underlying level of an attribute, does the item give the same score in different subgroups or is it biased towards one subgroup or another. The aim of the study was to explore DIF in the Likert format WOMAC for the first time in a UK osteoarthritis population with respect to demographic, social, clinical and psychological factors. Methods The sample comprised a community sample of 763 people with osteoarthritis who participated in the Somerset and Avon Survey of Health. The WOMAC was explored for DIF by gender, age, social deprivation, social class, employment status, distress, body mass index and clinical factors. Ordinal regression models were used to identify DIF items. Results After adjusting for age, two items were identified for the physical functioning subscale as having DIF with age identified as the DIF factor for 2 items, gender for 1 item and body mass index for 1 item. For the WOMAC pain subscale, for people with hip osteoarthritis one item was identified with age-related DIF. The impact of the DIF items rarely had a significant effect on the conclusions of group comparisons. Conclusions Overall, the WOMAC performed well with only a small number of DIF items identified. However, as DIF items were identified in for the WOMAC physical functioning subscale it would be advisable to analyse data taking into account the possible impact of the DIF items when weight, gender or especially age effects, are the focus of interest in UK-based osteoarthritis studies. Similarly for the WOMAC pain subscale in people with hip osteoarthritis it would be worthwhile to analyse data taking into account the

  17. FIM-Minimum Data Set Motor Item Bank: Short Forms Development and Precision Comparison in Veterans.

    Science.gov (United States)

    Li, Chih-Ying; Romero, Sergio; Simpson, Annie N; Bonilha, Heather S; Simpson, Kit N; Hong, Ickpyo; Velozo, Craig A

    2018-03-01

    To improve the practical use of the short forms (SFs) developed from the item bank, we compared the measurement precision of the 4- and 8-item SFs generated from a motor item bank composed of the FIM and the Minimum Data Set (MDS). The FIM-MDS motor item bank allowed scores generated from different instruments to be co-calibrated. The 4- and 8-item SFs were developed based on Rasch analysis procedures. This article compared person strata, ceiling/floor effects, and test SE plots for each administration form and examined 95% confidence interval error bands of anchored person measures with the corresponding SFs. We used 0.3 SE as a criterion to reflect a reliability level of .90. Veterans' inpatient rehabilitation facilities and community living centers. Veterans (N=2500) who had both FIM and the MDS data within 6 days during 2008 through 2010. Not applicable. Four- and 8-item SFs of FIM, MDS, and FIM-MDS motor item bank. Six SFs were generated with 4 and 8 items across a range of difficulty levels from the FIM-MDS motor item bank. The three 8-item SFs all had higher correlations with the item bank (r=.82-.95), higher person strata, and less test error than the corresponding 4-item SFs (r=.80-.90). The three 4-item SFs did not meet the criteria of SE bank composed of existing instruments across the continuum of care in veterans. We also found that the number of items, not test specificity, determines the precision of the instrument. Copyright © 2017 American Congress of Rehabilitation Medicine. All rights reserved.

  18. Examining the Effect of Reverse Worded Items on the Factor Structure of the Need for Cognition Scale.

    Directory of Open Access Journals (Sweden)

    Xijuan Zhang

    Full Text Available Reverse worded (RW items are often used to reduce or eliminate acquiescence bias, but there is a rising concern about their harmful effects on the covariance structure of the scale. Therefore, results obtained via traditional covariance analyses may be distorted. This study examined the effect of the RW items on the factor structure of the abbreviated 18-item Need for Cognition (NFC scale using confirmatory factor analysis. We modified the scale to create three revised versions, varying from no RW items to all RW items. We also manipulated the type of the RW items (polar opposite vs. negated. To each of the four scales, we fit four previously developed models. The four models included a 1-factor model, a 2-factor model distinguishing between positively worded (PW items and RW items, and two 2-factor models, each with one substantive factor and one method factor. Results showed that the number and type of the RW items affected the factor structure of the NFC scale. Consistent with previous research findings, for the original NFC scale, which contains both PW and RW items, the 1-factor model did not have good fit. In contrast, for the revised scales that had no RW items or all RW items, the 1-factor model had reasonably good fit. In addition, for the scale with polar opposite and negated RW items, the factor model with a method factor among the polar opposite items had considerably better fit than the 1-factor model.

  19. Evaluation of psychometric properties and differential item functioning of 8-item Child Perceptions Questionnaires using item response theory.

    Science.gov (United States)

    Yau, David T W; Wong, May C M; Lam, K F; McGrath, Colman

    2015-08-19

    Four-factor structure of the two 8-item short forms of Child Perceptions Questionnaire CPQ11-14 (RSF:8 and ISF:8) has been confirmed. However, the sum scores are typically reported in practice as a proxy of Oral health-related Quality of Life (OHRQoL), which implied a unidimensional structure. This study first assessed the unidimensionality of 8-item short forms of CPQ11-14. Item response theory (IRT) was employed to offer an alternative and complementary approach of validation and to overcome the limitations of classical test theory assumptions. A random sample of 649 12-year-old school children in Hong Kong was analyzed. Unidimensionality of the scale was tested by confirmatory factor analysis (CFA), principle component analysis (PCA) and local dependency (LD) statistic. Graded response model was fitted to the data. Contribution of each item to the scale was assessed by item information function (IIF). Reliability of the scale was assessed by test information function (TIF). Differential item functioning (DIF) across gender was identified by Wald test and expected score functions. Both CPQ11-14 RSF:8 and ISF:8 did not deviate much from the unidimensionality assumption. Results from CFA indicated acceptable fit of the one-factor model. PCA indicated that the first principle component explained >30 % of the total variation with high factor loadings for both RSF:8 and ISF:8. Almost all LD statistic items suggesting little contribution of information to the scale and item removal caused little practical impact. Comparing the TIFs, RSF:8 showed slightly better information than ISF:8. In addition to oral symptoms items, the item "Concerned with what other people think" demonstrated a uniform DIF (p Items related to oral symptoms were not informative to OHRQoL and deletion of these items is suggested. The impact of DIF across gender on the overall score was minimal. CPQ11-14 RSF:8 performed slightly better than ISF:8 in measurement precision. The 6-item short forms

  20. 38 CFR 3.1606 - Transportation items.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Transportation items. 3... Burial Benefits § 3.1606 Transportation items. The transportation costs of those persons who come within... shipment. (6) Cost of transportation by common carrier including amounts paid as Federal taxes. (7) Cost of...

  1. Binomial test models and item difficulty

    NARCIS (Netherlands)

    van der Linden, Willem J.

    1979-01-01

    In choosing a binomial test model, it is important to know exactly what conditions are imposed on item difficulty. In this paper these conditions are examined for both a deterministic and a stochastic conception of item responses. It appears that they are more restrictive than is generally

  2. Comparison on Computed Tomography using industrial items

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; De Chiffre, Leonardo

    2014-01-01

    In a comparison involving 27 laboratories from 8 countries, measurements on two common industrial items, a polymer part and a metal part, were carried out using X-ray Computed Tomography. All items were measured using coordinate measuring machines before and after circulation, with reference...

  3. Factoring handedness data: I. Item analysis.

    Science.gov (United States)

    Messinger, H B; Messinger, M I

    1995-12-01

    Recently in this journal Peters and Murphy challenged the validity of factor analyses done on bimodal handedness data, suggesting instead that right- and left-handers be studied separately. But bimodality may be avoidable if attention is paid to Oldfield's questionnaire format and instructions for the subjects. Two characteristics appear crucial: a two-column LEFT-RIGHT format for the body of the instrument and what we call Oldfield's Admonition: not to indicate strong preference for handedness item, such as write, unless "... the preference is so strong that you would never try to use the other hand unless absolutely forced to...". Attaining unimodality of an item distribution would seem to overcome the objections of Peters and Murphy. In a 1984 survey in Boston we used Oldfield's ten-item questionnaire exactly as published. This produced unimodal item distributions. With reflection of the five-point item scale and a logarithmic transformation, we achieved a degree of normalization for the items. Two surveys elsewhere based on Oldfield's 20-item list but with changes in the questionnaire format and the instructions, yielded markedly different item distributions with peaks at each extreme and sometimes in the middle as well.

  4. Item Information in the Rasch Model

    NARCIS (Netherlands)

    Engelen, Ron J.H.; van der Linden, Willem J.; Oosterloo, Sebe J.

    1988-01-01

    Fisher's information measure for the item difficulty parameter in the Rasch model and its marginal and conditional formulations are investigated. It is shown that expected item information in the unconditional model equals information in the marginal model, provided the assumption of sampling

  5. A Comparison of Multidimensional Item Selection Methods in Simple and Complex Test Designs

    Directory of Open Access Journals (Sweden)

    Eren Halil ÖZBERK

    2017-03-01

    Full Text Available In contrast with the previous studies, this study employed various test designs (simple and complex which allow the evaluation of the overall ability score estimations across multiple real test conditions. In this study, four factors were manipulated, namely the test design, number of items per dimension, correlation between dimensions and item selection methods. Using the generated item and ability parameters, dichotomous item responses were generated in by using M3PL compensatory multidimensional IRT model with specified correlations. MCAT composite ability score accuracy was evaluated using absolute bias (ABSBIAS, correlation and the root mean square error (RMSE between true and estimated ability scores. The results suggest that the multidimensional test structure, number of item per dimension and correlation between dimensions had significant effect on item selection methods for the overall score estimations. For simple structure test design it was found that V1 item selection has the lowest absolute bias estimations for both long and short tests while estimating overall scores. As the model gets complex KL item selection method performed better than other two item selection method.

  6. Software Note: Using BILOG for Fixed-Anchor Item Calibration

    Science.gov (United States)

    DeMars, Christine E.; Jurich, Daniel P.

    2012-01-01

    The nonequivalent groups anchor test (NEAT) design is often used to scale item parameters from two different test forms. A subset of items, called the anchor items or common items, are administered as part of both test forms. These items are used to adjust the item calibrations for any differences in the ability distributions of the groups taking…

  7. The randomly renewed general item and the randomly inspected item with exponential life distribution

    International Nuclear Information System (INIS)

    Schneeweiss, W.G.

    1979-01-01

    For a randomly renewed item the probability distributions of the time to failure and of the duration of down time and the expectations of these random variables are determined. Moreover, it is shown that the same theory applies to randomly checked items with exponential probability distribution of life such as electronic items. The case of periodic renewals is treated as an example. (orig.) [de

  8. Computerized Adaptive Test (CAT) Applications and Item Response Theory Models for Polytomous Items

    Science.gov (United States)

    Aybek, Eren Can; Demirtasli, R. Nukhet

    2017-01-01

    This article aims to provide a theoretical framework for computerized adaptive tests (CAT) and item response theory models for polytomous items. Besides that, it aims to introduce the simulation and live CAT software to the related researchers. Computerized adaptive test algorithm, assumptions of item response theory models, nominal response…

  9. Evaluation of Northwest University, Kano Post-UTME Test Items Using Item Response Theory

    Science.gov (United States)

    Bichi, Ado Abdu; Hafiz, Hadiza; Bello, Samira Abdullahi

    2016-01-01

    High-stakes testing is used for the purposes of providing results that have important consequences. Validity is the cornerstone upon which all measurement systems are built. This study applied the Item Response Theory principles to analyse Northwest University Kano Post-UTME Economics test items. The developed fifty (50) economics test items was…

  10. Asymptotic Standard Errors for Item Response Theory True Score Equating of Polytomous Items

    Science.gov (United States)

    Cher Wong, Cheow

    2015-01-01

    Building on previous works by Lord and Ogasawara for dichotomous items, this article proposes an approach to derive the asymptotic standard errors of item response theory true score equating involving polytomous items, for equivalent and nonequivalent groups of examinees. This analytical approach could be used in place of empirical methods like…

  11. The Effects of Test Length and Sample Size on Item Parameters in Item Response Theory

    Science.gov (United States)

    Sahin, Alper; Anil, Duygu

    2017-01-01

    This study investigates the effects of sample size and test length on item-parameter estimation in test development utilizing three unidimensional dichotomous models of item response theory (IRT). For this purpose, a real language test comprised of 50 items was administered to 6,288 students. Data from this test was used to obtain data sets of…

  12. Investigating Separate and Concurrent Approaches for Item Parameter Drift in 3PL Item Response Theory Equating

    Science.gov (United States)

    Arce-Ferrer, Alvaro J.; Bulut, Okan

    2017-01-01

    This study examines separate and concurrent approaches to combine the detection of item parameter drift (IPD) and the estimation of scale transformation coefficients in the context of the common item nonequivalent groups design with the three-parameter item response theory equating. The study uses real and synthetic data sets to compare the two…

  13. The Technical Quality of Test Items Generated Using a Systematic Approach to Item Writing.

    Science.gov (United States)

    Siskind, Theresa G.; Anderson, Lorin W.

    The study was designed to examine the similarity of response options generated by different item writers using a systematic approach to item writing. The similarity of response options to student responses for the same item stems presented in an open-ended format was also examined. A non-systematic (subject matter expertise) approach and a…

  14. Calorie Changes in Large Chain Restaurants: Declines in New Menu Items but Room for Improvement.

    Science.gov (United States)

    Bleich, Sara N; Wolfson, Julia A; Jarlenski, Marian P

    2016-01-01

    Large chain restaurants reduced the number of calories in newly introduced menu items in 2013 by about 60 calories (or 12%) relative to 2012. This paper describes trends in calories available in large U.S. chain restaurants to understand whether previously documented patterns persist. Data (a census of items for included restaurants) were obtained from the MenuStat project. This analysis included 66 of the 100 largest U.S. restaurants that are available in all three of the data years (2012-2014; N=23,066 items). Generalized linear models were used to examine: (1) per-item calorie changes from 2012 to 2014 among items on the menu in all years; and (2) mean calories in new items in 2013 and 2014 compared with items on the menu in 2012 only. Data were analyzed in 2014. Overall, calories in newly introduced menu items declined by 71 (or 15%) from 2012 to 2013 (p=0.001) and by 69 (or 14%) from 2012 to 2014 (p=0.03). These declines were concentrated mainly in new main course items (85 fewer calories in 2013 and 55 fewer calories in 2014; p=0.01). Although average calories in newly introduced menu items are declining, they are higher than items common to the menu in all 3 years. No differences in mean calories among items on menus in 2012, 2013, or 2014 were found. The previously observed declines in newly introduced menu items among large restaurant chains have been maintained, which suggests the beginning of a trend toward reducing calories. Copyright © 2016 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  15. Automated Item Generation with Recurrent Neural Networks.

    Science.gov (United States)

    von Davier, Matthias

    2018-03-12

    Utilizing technology for automated item generation is not a new idea. However, test items used in commercial testing programs or in research are still predominantly written by humans, in most cases by content experts or professional item writers. Human experts are a limited resource and testing agencies incur high costs in the process of continuous renewal of item banks to sustain testing programs. Using algorithms instead holds the promise of providing unlimited resources for this crucial part of assessment development. The approach presented here deviates in several ways from previous attempts to solve this problem. In the past, automatic item generation relied either on generating clones of narrowly defined item types such as those found in language free intelligence tests (e.g., Raven's progressive matrices) or on an extensive analysis of task components and derivation of schemata to produce items with pre-specified variability that are hoped to have predictable levels of difficulty. It is somewhat unlikely that researchers utilizing these previous approaches would look at the proposed approach with favor; however, recent applications of machine learning show success in solving tasks that seemed impossible for machines not too long ago. The proposed approach uses deep learning to implement probabilistic language models, not unlike what Google brain and Amazon Alexa use for language processing and generation.

  16. No evidence for an item limit in change detection.

    Directory of Open Access Journals (Sweden)

    Shaiyan Keshvari

    Full Text Available Change detection is a classic paradigm that has been used for decades to argue that working memory can hold no more than a fixed number of items ("item-limit models". Recent findings force us to consider the alternative view that working memory is limited by the precision in stimulus encoding, with mean precision decreasing with increasing set size ("continuous-resource models". Most previous studies that used the change detection paradigm have ignored effects of limited encoding precision by using highly discriminable stimuli and only large changes. We conducted two change detection experiments (orientation and color in which change magnitudes were drawn from a wide range, including small changes. In a rigorous comparison of five models, we found no evidence of an item limit. Instead, human change detection performance was best explained by a continuous-resource model in which encoding precision is variable across items and trials even at a given set size. This model accounts for comparison errors in a principled, probabilistic manner. Our findings sharply challenge the theoretical basis for most neural studies of working memory capacity.

  17. Building an Evaluation Scale using Item Response Theory.

    Science.gov (United States)

    Lalor, John P; Wu, Hao; Yu, Hong

    2016-11-01

    Evaluation of NLP methods requires testing against a previously vetted gold-standard test set and reporting standard metrics (accuracy/precision/recall/F1). The current assumption is that all items in a given test set are equal with regards to difficulty and discriminating power. We propose Item Response Theory (IRT) from psychometrics as an alternative means for gold-standard test-set generation and NLP system evaluation. IRT is able to describe characteristics of individual items - their difficulty and discriminating power - and can account for these characteristics in its estimation of human intelligence or ability for an NLP task. In this paper, we demonstrate IRT by generating a gold-standard test set for Recognizing Textual Entailment. By collecting a large number of human responses and fitting our IRT model, we show that our IRT model compares NLP systems with the performance in a human population and is able to provide more insight into system performance than standard evaluation metrics. We show that a high accuracy score does not always imply a high IRT score, which depends on the item characteristics and the response pattern.

  18. Selection of material balance areas and item control areas

    International Nuclear Information System (INIS)

    1975-04-01

    Section 70.58, ''Fundamental Nuclear Material Controls,'' of 10 CFR Part 70, ''Special Nuclear Material,'' requires certain licensees authorized to possess more than one effective kilogram of special nuclear material to establish Material Balance Areas (MBAs) or Item Control Areas (ICAs) for the physical and administrative control of nuclear materials. This section requires that: (1) each MBA be an identifiable physical area such that the quantity of nuclear material being moved into or out of the MBA is represented by a measured value; (2) the number of MBAs be sufficient to localize nuclear material losses or thefts and identify the mechanisms; (3) the custody of all nuclear material within an MBA or ICA be the responsibility of a single designated individual; and (4) ICAs be established according to the same criteria as MBAs except that control into and out of such areas would be by item identity and count for previously determined special nuclear material quantities, the validity of which must be ensured by tamper-safing unless the items are sealed sources. This guide describes bases acceptable to the NRC staff for the selection of material balance areas and item control areas. (U.S.)

  19. Working memory for sequences of temporal durations reveals a volatile single-item store

    Directory of Open Access Journals (Sweden)

    Sanjay G Manohar

    2016-10-01

    Full Text Available When a sequence is held in working memory, different items are retained with differing fidelity. Here we ask whether a sequence of brief time intervals that must be remembered show recency effects, similar to those observed in verbal and visuospatial working memory. It has been suggested that prioritising some items over others can be accounted for by a focus of attention, maintaining some items in a privileged state. We therefore also investigated whether such benefits are vulnerable to disruption by attention or expectation. Participants listened to sequences of one to five tones, of varying durations (200ms to 2s. Subsequently, the length of one of the tones in the sequence had to be reproduced by holding a key. The discrepancy between the reproduced and actual durations quantified the fidelity of memory for auditory durations. Recall precision decreased with the number of items that had to be remembered, and was better for the first and last items of sequences, in line with set-size and serial position effects seen in other modalities. To test whether attentional filtering demands might impair performance, an irrelevant variation in pitch was introduced in some blocks of trials. In those blocks, memory precision was worse for sequences that consisted of only one item, i.e. the smallest memory set size. Thus, when irrelevant information was present, the benefit of having only one item in memory is attenuated. Finally we examined whether expectation could interfere with memory. On half the trials, the number of items in the upcoming sequence was cued. When the number of items was known in advance, performance was paradoxically worse when the sequence consisted of only one item. Thus the benefit of having only one item to remember is stronger when it is unexpectedly the only item. Our results suggest that similar mechanisms are used to hold auditory time durations in working memory, as for visual or verbal stimuli. Further, solitary items were

  20. Basic Stand Alone Carrier Line Items PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Carrier Line Items Public Use Files (PUF) with information from Medicare Carrier claims. The CMS BSA Carrier Line...

  1. Extending item response theory to online homework

    Directory of Open Access Journals (Sweden)

    Gerd Kortemeyer

    2014-05-01

    Full Text Available Item response theory (IRT becomes an increasingly important tool when analyzing “big data” gathered from online educational venues. However, the mechanism was originally developed in traditional exam settings, and several of its assumptions are infringed upon when deployed in the online realm. For a large-enrollment physics course for scientists and engineers, the study compares outcomes from IRT analyses of exam and homework data, and then proceeds to investigate the effects of each confounding factor introduced in the online realm. It is found that IRT yields the correct trends for learner ability and meaningful item parameters, yet overall agreement with exam data is moderate. It is also found that learner ability and item discrimination is robust over a wide range with respect to model assumptions and introduced noise. Item difficulty is also robust, but over a narrower range.

  2. Inventions on presenting textual items in Graphical User Interface

    OpenAIRE

    Mishra, Umakant

    2014-01-01

    Although a GUI largely replaces textual descriptions by graphical icons, the textual items are not completely removed. The textual items are inevitably used in window titles, message boxes, help items, menu items and popup items. Textual items are necessary for communicating messages that are beyond the limitation of graphical messages. However, it is necessary to harness the textual items on the graphical interface in such a way that they complement each other to produce the best effect. One...

  3. Refinement of the Brazilian Household Food Insecurity Measurement Scale: Recommendation for a 14-item EBIA

    Directory of Open Access Journals (Sweden)

    Ana Maria Segall-Corrêa

    2014-04-01

    Full Text Available OBJECTIVE: To review and refine Brazilian Household Food Insecurity Measurement Scale structure. METHODS: The study analyzed the impact of removing the item "adult lost weight" and one of two possibly redundant items on Brazilian Household Food Insecurity Measurement Scale psychometric behavior using the one-parameter logistic (Rasch model. Brazilian Household Food Insecurity Measurement Scale psychometric behavior was analyzed with respect to acceptable adjustment values ranging from 0.7 to 1.3, and to severity scores of the items with theoretically expected gradients. The socioeconomic and food security indicators came from the 2004 National Household Sample Survey, which obtained complete answers to Brazilian Household Food Insecurity Measurement Scale items from 112,665 households. RESULTS: Removing the items "adult reduced amount..." followed by "adult ate less..." did not change the infit of the remaining items, except for "adult lost weight", whose infit increased from 1.21 to 1.56. The internal consistency and item severity scores did not change when "adult ate less" and one of the two redundant items were removed. CONCLUSION: Brazilian Household Food Insecurity Measurement Scale reanalysis reduced the number of scale items from 16 to 14 without changing its internal validity. Its use as a nationwide household food security measure is strongly recommended.

  4. A confirmative clinimetric analysis of the 36-item Family Assessment Device.

    Science.gov (United States)

    Timmerby, Nina; Cosci, Fiammetta; Watson, Maggie; Csillag, Claudio; Schmitt, Florence; Steck, Barbara; Bech, Per; Thastum, Mikael

    2018-02-07

    The Family Assessment Device (FAD) is a 60-item questionnaire widely used to evaluate self-reported family functioning. However, the factor structure as well as the number of items has been questioned. A shorter and more user-friendly version of the original FAD-scale, the 36-item FAD, has therefore previously been proposed, based on findings in a nonclinical population of adults. We aimed in this study to evaluate the brief 36-item version of the FAD in a clinical population. Data from a European multinational study, examining factors associated with levels of family functioning in adult cancer patients' families, were used. Both healthy and ill parents completed the 60-item version FAD. The psychometric analyses conducted were Principal Component Analysis and Mokken-analysis. A total of 564 participants were included. Based on the psychometric analysis we confirmed that the 36-item version of the FAD has robust psychometric properties and can be used in clinical populations. The present analysis confirmed that the 36-item version of the FAD (18 items assessing 'well-being' and 18 items assessing 'dysfunctional' family function) is a brief scale where the summed total score is a valid measure of the dimensions of family functioning. This shorter version of the FAD is, in accordance with the concept of 'measurement-based care', an easy to use scale that could be considered when the aim is to evaluate self-reported family functioning.

  5. Psychometric properties of the Triarchic Psychopathy Measure: An item response theory approach.

    Science.gov (United States)

    Shou, Yiyun; Sellbom, Martin; Xu, Jing

    2018-05-01

    There is cumulative evidence for the cross-cultural validity of the Triarchic Psychopathy Measure (TriPM; Patrick, 2010) among non-Western populations. Recent studies using correlational and regression analyses show promising construct validity of the TriPM in Chinese samples. However, little is known about the efficiency of items in TriPM in assessing the proposed latent traits. The current study evaluated the psychometric properties of the Chinese TriPM at the item level using item response theory analyses. It also examined the measurement invariance of the TriPM between the Chinese and the U.S. student samples by applying differential item functioning analyses under the item response theory framework. The results supported the unidimensional nature of the Disinhibition and Meanness scales. Both scales had a greater level of precision in the respective underlying constructs at the positive ends. The two scales, however, had several items that were weakly associated with their respective latent traits in the Chinese student sample. Boldness, on the other hand, was found to be multidimensional, and reflected a more normally distributed range of variation. The examination of measurement bias via differential item functioning analyses revealed that a number of items of the TriPM were not equivalent across the Chinese and the U.S. Some modification and adaptation of items might be considered for improving the precision of the TriPM for Chinese participants. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  6. An Effective Multimedia Item Shell Design for Individualized Education: The Crome Project

    Directory of Open Access Journals (Sweden)

    Irene Cheng

    2008-01-01

    Full Text Available There are several advantages to creating multimedia item types and applying computer-based adaptive testing in education. First is the capability to motivate learning by making the learners feel more engaged and in an interactive environment. Second is a better concept representation, which is not possible in conventional multiple-choice tests. Third is the advantage of individualized curriculum design, rather than a curriculum designed for an average student. Fourth is a good choice of the next question, associated with the appropriate difficulty level based on a student's response to the current question. However, many issues need to be addressed when achieving these goals, including: (a the large number of item types required to represent the current multiple-choice questions in multimedia formats, (b the criterion used to determine the difficulty level of a multimedia question item, and (c the methodology applied to the question selection process for individual students. In this paper, we propose a multimedia item shell design that not only reduces the number of item types required, but also computes difficulty level of an item automatically. The concept of question seed is introduced to make content creation more cost-effective. The proposed item shell framework facilitates efficient communication between user responses at the client, and the scoring agents integrated with a student ability assessor at the server. We also describe approaches for automatically estimating difficulty level of questions, and discuss preliminary evaluation of multimedia item types by students.

  7. The role of attention in item-item binding in visual working memory.

    Science.gov (United States)

    Peterson, Dwight J; Naveh-Benjamin, Moshe

    2017-09-01

    An important yet unresolved question regarding visual working memory (VWM) relates to whether or not binding processes within VWM require additional attentional resources compared with processing solely the individual components comprising these bindings. Previous findings indicate that binding of surface features (e.g., colored shapes) within VWM is not demanding of resources beyond what is required for single features. However, it is possible that other types of binding, such as the binding of complex, distinct items (e.g., faces and scenes), in VWM may require additional resources. In 3 experiments, we examined VWM item-item binding performance under no load, articulatory suppression, and backward counting using a modified change detection task. Binding performance declined to a greater extent than single-item performance under higher compared with lower levels of concurrent load. The findings from each of these experiments indicate that processing item-item bindings within VWM requires a greater amount of attentional resources compared with single items. These findings also highlight an important distinction between the role of attention in item-item binding within VWM and previous studies of long-term memory (LTM) where declines in single-item and binding test performance are similar under divided attention. The current findings provide novel evidence that the specific type of binding is an important determining factor regarding whether or not VWM binding processes require attention. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  8. Investigating the Impact of Item Parameter Drift for Item Response Theory Models with Mixture Distributions.

    Science.gov (United States)

    Park, Yoon Soo; Lee, Young-Sun; Xing, Kuan

    2016-01-01

    This study investigates the impact of item parameter drift (IPD) on parameter and ability estimation when the underlying measurement model fits a mixture distribution, thereby violating the item invariance property of unidimensional item response theory (IRT) models. An empirical study was conducted to demonstrate the occurrence of both IPD and an underlying mixture distribution using real-world data. Twenty-one trended anchor items from the 1999, 2003, and 2007 administrations of Trends in International Mathematics and Science Study (TIMSS) were analyzed using unidimensional and mixture IRT models. TIMSS treats trended anchor items as invariant over testing administrations and uses pre-calibrated item parameters based on unidimensional IRT. However, empirical results showed evidence of two latent subgroups with IPD. Results also showed changes in the distribution of examinee ability between latent classes over the three administrations. A simulation study was conducted to examine the impact of IPD on the estimation of ability and item parameters, when data have underlying mixture distributions. Simulations used data generated from a mixture IRT model and estimated using unidimensional IRT. Results showed that data reflecting IPD using mixture IRT model led to IPD in the unidimensional IRT model. Changes in the distribution of examinee ability also affected item parameters. Moreover, drift with respect to item discrimination and distribution of examinee ability affected estimates of examinee ability. These findings demonstrate the need to caution and evaluate IPD using a mixture IRT framework to understand its effects on item parameters and examinee ability.

  9. Investigating the Impact of Item Parameter Drift for Item Response Theory Models with Mixture Distributions

    Directory of Open Access Journals (Sweden)

    Yoon Soo ePark

    2016-02-01

    Full Text Available This study investigates the impact of item parameter drift (IPD on parameter and ability estimation when the underlying measurement model fits a mixture distribution, thereby violating the item invariance property of unidimensional item response theory (IRT models. An empirical study was conducted to demonstrate the occurrence of both IPD and an underlying mixture distribution using real-world data. Twenty-one trended anchor items from the 1999, 2003, and 2007 administrations of Trends in International Mathematics and Science Study (TIMSS were analyzed using unidimensional and mixture IRT models. TIMSS treats trended anchor items as invariant over testing administrations and uses pre-calibrated item parameters based on unidimensional IRT. However, empirical results showed evidence of two latent subgroups with IPD. Results showed changes in the distribution of examinee ability between latent classes over the three administrations. A simulation study was conducted to examine the impact of IPD on the estimation of ability and item parameters, when data have underlying mixture distributions. Simulations used data generated from a mixture IRT model and estimated using unidimensional IRT. Results showed that data reflecting IPD using mixture IRT model led to IPD in the unidimensional IRT model. Changes in the distribution of examinee ability also affected item parameters. Moreover, drift with respect to item discrimination and distribution of examinee ability affected estimates of examinee ability. These findings demonstrate the need to caution and evaluate IPD using a mixture IRT framework to understand its effect on item parameters and examinee ability.

  10. Calorie changes in chain restaurant menu items: implications for obesity and evaluations of menu labeling.

    Science.gov (United States)

    Bleich, Sara N; Wolfson, Julia A; Jarlenski, Marian P

    2015-01-01

    Supply-side reductions to the calories in chain restaurants are a possible benefit of upcoming menu labeling requirements. To describe trends in calories available in large U.S. restaurants. Data were obtained from the MenuStat project, a census of menu items in 66 of the 100 largest U.S. restaurant chains, for 2012 and 2013 (N=19,417 items). Generalized linear models were used to calculate (1) the mean change in calories from 2012 to 2013, among items on the menu in both years; and (2) the difference in mean calories, comparing newly introduced items to those on the menu in 2012 only (overall and between core versus non-core items). Data were analyzed in 2014. Mean calories among items on menus in both 2012 and 2013 did not change. Large restaurant chains in the U.S. have recently had overall declines in calories in newly introduced menu items (-56 calories, 12% decline). These declines were concentrated mainly in new main course items (-67 calories, 10% decline). New beverage (-26 calories, 8% decline) and children's (-46 calories, 20% decline) items also had fewer mean calories. Among chain restaurants with a specific focus (e.g., burgers), average calories in new menu items not core to the business declined more than calories in core menu items. Large chain restaurants significantly reduced the number of calories in newly introduced menu items. Supply-side changes to the calories in chain restaurants may have a significant impact on obesity prevention. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  11. Calibration of the PROMIS physical function item bank in Dutch patients with rheumatoid arthritis.

    Directory of Open Access Journals (Sweden)

    Martijn A H Oude Voshaar

    Full Text Available OBJECTIVE: To calibrate the Dutch-Flemish version of the PROMIS physical function (PF item bank in patients with rheumatoid arthritis (RA and to evaluate cross-cultural measurement equivalence with US general population and RA data. METHODS: Data were collected from RA patients enrolled in the Dutch DREAM registry. An incomplete longitudinal anchored design was used where patients completed all 121 items of the item bank over the course of three waves of data collection. Item responses were fit to a generalized partial credit model adapted for longitudinal data and the item parameters were examined for differential item functioning (DIF across country, age, and sex. RESULTS: In total, 690 patients participated in the study at time point 1 (T2, N = 489; T3, N = 311. The item bank could be successfully fitted to a generalized partial credit model, with the number of misfitting items falling within acceptable limits. Seven items demonstrated DIF for sex, while 5 items showed DIF for age in the Dutch RA sample. Twenty-five (20% items were flagged for cross-cultural DIF compared to the US general population. However, the impact of observed DIF on total physical function estimates was negligible. DISCUSSION: The results of this study showed that the PROMIS PF item bank adequately fit a unidimensional IRT model which provides support for applications that require invariant estimates of physical function, such as computer adaptive testing and targeted short forms. More studies are needed to further investigate the cross-cultural applicability of the US-based PROMIS calibration and standardized metric.

  12. Item response theory analysis of Centers for Disease Control and Prevention Health-Related Quality of Life (CDC HRQOL) items in adults with arthritis.

    Science.gov (United States)

    Mielenz, Thelma J; Callahan, Leigh F; Edwards, Michael C

    2016-03-12

    Examine the feasibility of performing an item response theory (IRT) analysis on two of the Centers for Disease Control and Prevention health-related quality of life (CDC HRQOL) modules - the 4-item Healthy Days Core Module (HDCM) and the 5-item Healthy days Symptoms Module (HDSM). Previous principal components analyses confirm that the two scales both assess a mix of mental (CDC-MH) and physical health (CDC-PH). The purpose is to conduct item response theory (IRT) analysis on the CDC-MH and CDC-PH scales separately. 2182 patients with self-reported or physician-diagnosed arthritis completed a cross-sectional survey including HDCM and HDSM items. Besides global health, the other 8 items ask the number of days that some statement was true; we chose to recode the data into 8 categories based on observed clustering. The IRT assumptions were assessed using confirmatory factor analysis and the data could be modeled using an unidimensional IRT model. The graded response model was used for IRT analyses and CDC-MH and CDC-PH scales were analyzed separately in flexMIRT. The IRT parameter estimates for the five-item CDC-PH all appeared reasonable. The three-item CDC-MH did not have reasonable parameter estimates. The CDC-PH scale is amenable to IRT analysis but the existing The CDC-MH scale is not. We suggest either using the 4-item Healthy Days Core Module (HDCM) and the 5-item Healthy days Symptoms Module (HDSM) as they currently stand or the CDC-PH scale alone if the primary goal is to measure physical health related HRQOL.

  13. Evaluation of item candidates for a diabetic retinopathy quality of life item bank.

    Science.gov (United States)

    Fenwick, Eva K; Pesudovs, Konrad; Khadka, Jyoti; Rees, Gwyn; Wong, Tien Y; Lamoureux, Ecosse L

    2013-09-01

    We are developing an item bank assessing the impact of diabetic retinopathy (DR) on quality of life (QoL) using a rigorous multi-staged process combining qualitative and quantitative methods. We describe here the first two qualitative phases: content development and item evaluation. After a comprehensive literature review, items were generated from four sources: (1) 34 previously validated patient-reported outcome measures; (2) five published qualitative articles; (3) eight focus groups and 18 semi-structured interviews with 57 DR patients; and (4) seven semi-structured interviews with diabetes or ophthalmic experts. Items were then evaluated during 3 stages, namely binning (grouping) and winnowing (reduction) based on key criteria and panel consensus; development of item stems and response options; and pre-testing of items via cognitive interviews with patients. The content development phase yielded 1,165 unique items across 7 QoL domains. After 3 sessions of binning and winnowing, items were reduced to a minimally representative set (n = 312) across 9 domains of QoL: visual symptoms; ocular surface symptoms; activity limitation; mobility; emotional; health concerns; social; convenience; and economic. After 8 cognitive interviews, 42 items were amended resulting in a final set of 314 items. We have employed a systematic approach to develop items for a DR-specific QoL item bank. The psychometric properties of the nine QoL subscales will be assessed using Rasch analysis. The resulting validated item bank will allow clinicians and researchers to better understand the QoL impact of DR and DR therapies from the patient's perspective.

  14. An NCME Instructional Module on Polytomous Item Response Theory Models

    Science.gov (United States)

    Penfield, Randall David

    2014-01-01

    A polytomous item is one for which the responses are scored according to three or more categories. Given the increasing use of polytomous items in assessment practices, item response theory (IRT) models specialized for polytomous items are becoming increasingly common. The purpose of this ITEMS module is to provide an accessible overview of…

  15. Loglinear multidimensional IRT models for polytomously scired Items

    NARCIS (Netherlands)

    Kelderman, Henk

    1988-01-01

    A loglinear item response theory (IRT) model is proposed that relates polytomously scored item responses to a multidimensional latent space. Each item may have a different response function where each item response may be explained by one or more latent traits. Item response functions may follow a

  16. A strategy for optimizing item-pool management

    NARCIS (Netherlands)

    Ariel, A.; van der Linden, Willem J.; Veldkamp, Bernard P.

    2006-01-01

    Item-pool management requires a balancing act between the input of new items into the pool and the output of tests assembled from it. A strategy for optimizing item-pool management is presented that is based on the idea of a periodic update of an optimal blueprint for the item pool to tune item

  17. AN EFFICIENT DATA MINING METHOD TO FIND FREQUENT ITEM SETS IN LARGE DATABASE USING TR- FCTM

    Directory of Open Access Journals (Sweden)

    Saravanan Suba

    2016-01-01

    Full Text Available Mining association rules in large database is one of most popular data mining techniques for business decision makers. Discovering frequent item set is the core process in association rule mining. Numerous algorithms are available in the literature to find frequent patterns. Apriori and FP-tree are the most common methods for finding frequent items. Apriori finds significant frequent items using candidate generation with more number of data base scans. FP-tree uses two database scans to find significant frequent items without using candidate generation. This proposed TR-FCTM (Transaction Reduction- Frequency Count Table Method discovers significant frequent items by generating full candidates once to form frequency count table with one database scan. Experimental results of TR-FCTM shows that this algorithm outperforms than Apriori and FP-tree.

  18. Verification of Differential Item Functioning (DIF) Status of West ...

    African Journals Online (AJOL)

    This study investigated test item bias and Differential Item Functioning (DIF) of West African ... items in chemistry function differentially with respect to gender and location. In Aba education zone of Abia, 50 secondary schools were purposively ...

  19. Conjunctive and Disjunctive Item Response Functions.

    Science.gov (United States)

    1984-10-01

    fed set ofvaluesof a, b, AI , B1 A2 2 . 2 A3 , and 13 , the f ’. g ’a. nd h’a in (7) are fied. Equation (7) must still hold for S - e19029e3,..* . Thus...for Item I Is -- b ?(a:1 , b1 ,O) (1 + ’)(I + e4 (22 where a and pi are arbitrary constants. These constants mst be the sam for all Items In a given...NETHERLIS I E3I1 Focility-Acquisitions 4133 Rugby Avnue 1 Lee Cronbach Bethesda, NO 20014 16 Laburnue Road Atherton, CA 94205 1 Dr. Benjamin A. Fairbank

  20. Item Analysis of Multiple Choice Questions at the Department of Paediatrics, Arabian Gulf University, Manama, Bahrain

    Directory of Open Access Journals (Sweden)

    Deena Kheyami

    2018-04-01

    Full Text Available Objectives: The current study aimed to carry out a post-validation item analysis of multiple choice questions (MCQs in medical examinations in order to evaluate correlations between item difficulty, item discrimination and distraction effectiveness so as to determine whether questions should be included, modified or discarded. In addition, the optimal number of options per MCQ was analysed. Methods: This cross-sectional study was performed in the Department of Paediatrics, Arabian Gulf University, Manama, Bahrain. A total of 800 MCQs and 4,000 distractors were analysed between November 2013 and June 2016. Results: The mean difficulty index ranged from 36.70–73.14%. The mean discrimination index ranged from 0.20–0.34. The mean distractor efficiency ranged from 66.50–90.00%. Of the items, 48.4%, 35.3%, 11.4%, 3.9% and 1.1% had zero, one, two, three and four nonfunctional distractors (NFDs, respectively. Using three or four rather than five options in each MCQ resulted in 95% or 83.6% of items having zero NFDs, respectively. The distractor efficiency was 91.87%, 85.83% and 64.13% for difficult, acceptable and easy items, respectively (P <0.005. Distractor efficiency was 83.33%, 83.24% and 77.56% for items with excellent, acceptable and poor discrimination, respectively (P <0.005. The average Kuder-Richardson formula 20 reliability coefficient was 0.76. Conclusion: A considerable number of the MCQ items were within acceptable ranges. However, some items needed to be discarded or revised. Using three or four rather than five options in MCQs is recommended to reduce the number of NFDs and improve the overall quality of the examination.

  1. AVOID BECOMING A VICTIM OF COUNTERFEIT ITEMS

    Energy Technology Data Exchange (ETDEWEB)

    WARRINER RD

    2011-07-13

    In today's globalized economy, we cannot live without imported products. Most people do not realize how thin the safety net of regulation and inspection really is. Less than three percent of imported products receive any form of government inspection prior to sale. Avoid flea markets, street vendors and deep discount stores. The sellers of counterfeit wares know where to market their products. They look for individuals who are hungry for a brand name item but do not want to pay a brand name price for it. The internet provides anonymity to the sellers of counterfeit products. Unlike Europe, U.S. law does not hold internet-marketing organizations, responsible for the quality of the products sold on their websites. These organizations will remove an individual vendor when a sufficient number of complaints are lodged, but they will not take responsibility for the counterfeit products you may have purchased. EBay has a number of counterfeit product guides to help you avoid being a victim of the sellers of these products. Ten percent of all medications taken worldwide are counterfeit. If you do buy medications on-line, be sure that the National Association of Boards of Pharmacy Verified Internet Pharmacy Practice Sites (VIPPS) recommends the pharmacy you choose to use. Inspect all medication purchases and report any change in color, shape, imprinting or odor to your pharmacist. If you take generic medications these attributes may change from one manufacturer to another. Your pharmacist should inform you of any changes when you refill your prescription. If they do not, get clarification prior to taking the medication. Please note that the Federal Drug Administration (FDA) does not regulate supplements. The FDA only steps in when a specific supplement proves to cause physical harm or contains a regulated ingredient. Due to counterfeiting, Underwriters Laboratories (UL) changed their label design three times since 1996. The new gold label should be attached to the cord

  2. A Comparison of the 27-Item and 12-Item Intolerance of Uncertainty Scales

    Science.gov (United States)

    Khawaja, Nigar G.; Yu, Lai Ngo Heidi

    2010-01-01

    The 27-item Intolerance of Uncertainty Scale (IUS) has become one of the most frequently used measures of Intolerance of Uncertainty. More recently, an abridged, 12-item version of the IUS has been developed. The current research used clinical (n = 50) and non-clinical (n = 56) samples to examine and compare the psychometric properties of both…

  3. Language-related differential item functioning between English and German PROMIS Depression items is negligible.

    Science.gov (United States)

    Fischer, H Felix; Wahl, Inka; Nolte, Sandra; Liegl, Gregor; Brähler, Elmar; Löwe, Bernd; Rose, Matthias

    2017-12-01

    To investigate differential item functioning (DIF) of PROMIS Depression items between US and German samples we compared data from the US PROMIS calibration sample (n = 780), a German general population survey (n = 2,500) and a German clinical sample (n = 621). DIF was assessed in an ordinal logistic regression framework, with 0.02 as criterion for R 2 -change and 0.096 for Raju's non-compensatory DIF. Item parameters were initially fixed to the PROMIS Depression metric; we used plausible values to account for uncertainty in depression estimates. Only four items showed DIF. Accounting for DIF led to negligible effects for the full item bank as well as a post hoc simulated computer-adaptive test (German general population sample was considerably lower compared to the US reference value of 50. Overall, we found little evidence for language DIF between US and German samples, which could be addressed by either replacing the DIF items by items not showing DIF or by scoring the short form in German samples with the corrected item parameters reported. Copyright © 2016 John Wiley & Sons, Ltd.

  4. Modeling Local Item Dependence in Cloze and Reading Comprehension Test Items Using Testlet Response Theory

    Science.gov (United States)

    Baghaei, Purya; Ravand, Hamdollah

    2016-01-01

    In this study the magnitudes of local dependence generated by cloze test items and reading comprehension items were compared and their impact on parameter estimates and test precision was investigated. An advanced English as a foreign language reading comprehension test containing three reading passages and a cloze test was analyzed with a…

  5. Effects of promotional materials on vending sales of low-fat items in teachers' lounges.

    Science.gov (United States)

    Fiske, Amy; Cullen, Karen Weber

    2004-01-01

    This study examined the impact of an environmental intervention in the form of promotional materials and increased availability of low-fat items on vending machine sales. Ten vending machines were selected and randomly assigned to one of three conditions: control, or one of two experimental conditions. Vending machines in the two intervention conditions received three additional low-fat selections. Low-fat items were promoted at two levels: labels (intervention I), and labels plus signs (intervention II). The number of individual items sold and the total revenue generated was recorded weekly for each machine for 4 weeks. Use of promotional materials resulted in a small, but not significant, increase in the number of low-fat items sold, although machine sales were not significantly impacted by the change in product selection. Results of this study, although not statistically significant, suggest that environmental change may be a realistic means of positively influencing consumer behavior.

  6. An emotional functioning item bank of 24 items for computerized adaptive testing (CAT) was established

    DEFF Research Database (Denmark)

    Petersen, Morten Aa.; Gamper, Eva-Maria; Costantini, Anna

    2016-01-01

    of the widely used EORTC Quality of Life questionnaire (QLQ-C30). STUDY DESIGN AND SETTING: On the basis of literature search and evaluations by international samples of experts and cancer patients, 38 candidate items were developed. The psychometric properties of the items were evaluated in a large...... international sample of cancer patients. This included evaluations of dimensionality, item response theory (IRT) model fit, differential item functioning (DIF), and of measurement precision/statistical power. RESULTS: Responses were obtained from 1,023 cancer patients from four countries. The evaluations showed...... that 24 items could be included in a unidimensional IRT model. DIF did not seem to have any significant impact on the estimation of EF. Evaluations indicated that the CAT measure may reduce sample size requirements by up to 50% compared to the QLQ-C30 EF scale without reducing power. CONCLUSION...

  7. Differential item functioning magnitude and impact measures from item response theory models.

    Science.gov (United States)

    Kleinman, Marjorie; Teresi, Jeanne A

    2016-01-01

    Measures of magnitude and impact of differential item functioning (DIF) at the item and scale level, respectively are presented and reviewed in this paper. Most measures are based on item response theory models. Magnitude refers to item level effect sizes, whereas impact refers to differences between groups at the scale score level. Reviewed are magnitude measures based on group differences in the expected item scores and impact measures based on differences in the expected scale scores. The similarities among these indices are demonstrated. Various software packages are described that provide magnitude and impact measures, and new software presented that computes all of the available statistics conveniently in one program with explanations of their relationships to one another.

  8. Toward a More Responsive Consumable Materiel Supply Chain: Leveraging New Metrics to Identify and Classify Items of Concern

    Science.gov (United States)

    2016-06-01

    MATERIEL SUPPLY CHAIN: LEVERAGING NEW METRICS TO IDENTIFY AND CLASSIFY ITEMS OF CONCERN by Andrew R. Haley June 2016 Thesis Advisor: Robert...IDENTIFY AND CLASSIFY ITEMS OF CONCERN 5. FUNDING NUMBERS 6. AUTHOR(S) Andrew R. Haley 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Naval...Supply Systems Command (NAVSUP), logistics, inventory, consumable, NSNs at Risk, Bad Actors, Bad Actors with Trend, items of concern , customer time

  9. A production inventory model with deteriorating items and shortages

    Directory of Open Access Journals (Sweden)

    Samanta G.P.

    2004-01-01

    Full Text Available A continuous production control inventory model for deteriorating items with shortages is developed. A number of structural properties of the inventory system are studied analytically. The formulae for the optimal average system cost, stock level, backlog level and production cycle time are derived when the deterioration rate is very small. Numerical examples are taken to illustrate the procedure of finding the optimal total inventory cost, stock level, backlog level and production cycle time. Sensitivity analysis is carried out to demonstrate the effects of changing parameter values on the optimal solution of the system.

  10. 47 CFR 32.7600 - Extraordinary items.

    Science.gov (United States)

    2010-10-01

    ... FOR TELECOMMUNICATIONS COMPANIES Instructions For Other Income Accounts § 32.7600 Extraordinary items... extraordinary. Extraordinary events and transactions are distinguished by both their unusual nature and by the infrequency of their occurrence, taking into account the environment in which the company operates. This...

  11. Random Item Generation Is Affected by Age

    Science.gov (United States)

    Multani, Namita; Rudzicz, Frank; Wong, Wing Yiu Stephanie; Namasivayam, Aravind Kumar; van Lieshout, Pascal

    2016-01-01

    Purpose: Random item generation (RIG) involves central executive functioning. Measuring aspects of random sequences can therefore provide a simple method to complement other tools for cognitive assessment. We examine the extent to which RIG relates to specific measures of cognitive function, and whether those measures can be estimated using RIG…

  12. In-Process Items on LCS.

    Science.gov (United States)

    Russell, Thyra K.

    Morris Library at Southern Illinois University computerized its technical processes using the Library Computer System (LCS), which was implemented in the library to streamline order processing by: (1) providing up-to-date online files to track in-process items; (2) encouraging quick, efficient accessing of information; (3) reducing manual files;…

  13. Algorithmic test design using classical item parameters

    NARCIS (Netherlands)

    van der Linden, Willem J.; Adema, Jos J.

    Two optimalization models for the construction of tests with a maximal value of coefficient alpha are given. Both models have a linear form and can be solved by using a branch-and-bound algorithm. The first model assumes an item bank calibrated under the Rasch model and can be used, for instance,

  14. Item Effects in Recognition Memory for Words

    Science.gov (United States)

    Freeman, Emily; Heathcote, Andrew; Chalmers, Kerry; Hockley, William

    2010-01-01

    We investigate the effects of word characteristics on episodic recognition memory using analyses that avoid Clark's (1973) "language-as-a-fixed-effect" fallacy. Our results demonstrate the importance of modeling word variability and show that episodic memory for words is strongly affected by item noise (Criss & Shiffrin, 2004), as measured by the…

  15. Extending Item Response Theory to Online Homework

    Science.gov (United States)

    Kortemeyer, Gerd

    2014-01-01

    Item response theory (IRT) becomes an increasingly important tool when analyzing "big data" gathered from online educational venues. However, the mechanism was originally developed in traditional exam settings, and several of its assumptions are infringed upon when deployed in the online realm. For a large-enrollment physics course for…

  16. Item Response Theory: A Basic Concept

    Science.gov (United States)

    Mahmud, Jumailiyah

    2017-01-01

    With the development in computing technology, item response theory (IRT) develops rapidly, and has become a user friendly application in psychometrics world. Limitation in classical theory is one aspect that encourages the use of IRT. In this study, the basic concept of IRT will be discussed. In addition, it will briefly review the ability…

  17. Item Response Theory for Peer Assessment

    Science.gov (United States)

    Uto, Masaki; Ueno, Maomi

    2016-01-01

    As an assessment method based on a constructivist approach, peer assessment has become popular in recent years. However, in peer assessment, a problem remains that reliability depends on the rater characteristics. For this reason, some item response models that incorporate rater parameters have been proposed. Those models are expected to improve…

  18. 77 FR 59339 - Acquisition of Commercial Items

    Science.gov (United States)

    2012-09-27

    ... DEPARTMENT OF DEFENSE Defense Acquisition Regulations System 48 CFR Part 212 Acquisition of Commercial Items CFR Correction 212.504 [Corrected] In Title 48 of the Code of Federal Regulations, Chapter 2 (Parts 201--299), revised as of October 1, 2011, on page 73, in section 212.504, paragraph (a) is...

  19. Bayesian item selection criteria for adaptive testing

    NARCIS (Netherlands)

    van der Linden, Willem J.

    1996-01-01

    R.J. Owen (1975) proposed an approximate empirical Bayes procedure for item selection in adaptive testing. The procedure replaces the true posterior by a normal approximation with closed-form expressions for its first two moments. This approximation was necessary to minimize the computational

  20. Aging and Confidence Judgments in Item Recognition

    Science.gov (United States)

    Voskuilen, Chelsea; Ratcliff, Roger; McKoon, Gail

    2018-01-01

    We examined the effects of aging on performance in an item-recognition experiment with confidence judgments. A model for confidence judgments and response time (RTs; Ratcliff & Starns, 2013) was used to fit a large amount of data from a new sample of older adults and a previously reported sample of younger adults. This model of confidence…

  1. 10 CFR 74.55 - Item monitoring.

    Science.gov (United States)

    2010-01-01

    ... Quantities of Strategic Special Nuclear Material § 74.55 Item monitoring. (a) Licensees subject to § 74.51... quantitatively measured, the validity of that measurement independently confirmed, and that additionally have..., except for reactor components measuring at least one meter in length and weighing in excess of 30...

  2. Grammatical typology and frequency analysis: number availability and number use

    Directory of Open Access Journals (Sweden)

    Dunstan Brown

    2013-12-01

    Full Text Available The Smith-Stark hierarchy, a version of the Animacy Hierarchy, offers a typology of the cross-linguistic availability of number. The hierarchy predicts that the availability of number is not arbitrary. For any language, if the expression of plural is available to a noun, it is available to any noun of a semantic category further to the left of the hierarchy. In this article we move one step further by showing that the structure of the hierarchy can be observed in a statistical model of number use in Russian. We also investigate three co-variates: plural preference, pluralia tantum and irregularity effects; these account for an item's behaviour being different than that solely expected from its animacy position.

  3. Interaction between numbers and size during visual search

    OpenAIRE

    Krause, Florian; Bekkering, Harold; Pratt, Jay; Lindemann, Oliver

    2016-01-01

    The current study investigates an interaction between numbers and physical size (i.e. size congruity) in visual search. In three experiments, participants had to detect a physically large (or small) target item among physically small (or large) distractors in a search task comprising single-digit numbers. The relative numerical size of the digits was varied, such that the target item was either among the numerically large or small numbers in the search display and the relation between numeric...

  4. What proportion of prescription items dispensed in community pharmacies are eligible for the New Medicine Service?

    Science.gov (United States)

    Wells, Katharine M; Boyd, Matthew J; Thornley, Tracey; Boardman, Helen F

    2014-03-07

    The payment structure for the New Medicine Service (NMS) in England is based on the assumption that 0.5% of prescription items dispensed in community pharmacies are eligible for the service. This assumption is based on a theoretical calculation. This study aimed to find out the actual proportion of prescription items eligible for the NMS dispensed in community pharmacies in order to compare this with the theoretical assumption. The study also aimed to investigate whether the proportion of prescription items eligible for the NMS is affected by pharmacies' proximity to GP practices. The study collected data from eight pharmacies in Nottingham belonging to the same large chain of pharmacies. Pharmacies were grouped by distance from the nearest GP practice and sampled to reflect the distribution by distance of all pharmacies in Nottingham. Data on one thousand consecutive prescription items were collected from each pharmacy and the number of NMS eligible items recorded. All NHS prescriptions were included in the sample. Data were analysed and proportions calculated with 95% confidence intervals used to compare the study results against the theoretical figure of 0.5% of prescription items being eligible for the NMS. A total of 8005 prescription items were collected (a minimum of 1000 items per pharmacy) of which 17 items were eligible to receive the service. The study found that 0.25% (95% confidence intervals: 0.14% to 0.36%) of prescription items were eligible for the NMS which differs significantly from the theoretical assumption of 0.5%. The opportunity rate for the service was lower, 0.21% (95% confidence intervals: 0.10% to 0.32%) of items, as some items eligible for the NMS did not translate into opportunities to offer the service. Of all the prescription items collected in the pharmacies, 28% were collected by patient representatives. The results of this study show that the proportion of items eligible for the NMS dispensed in community pharmacies is lower than

  5. Students' proficiency scores within multitrait item response theory

    Science.gov (United States)

    Scott, Terry F.; Schumayer, Daniel

    2015-12-01

    In this paper we present a series of item response models of data collected using the Force Concept Inventory. The Force Concept Inventory (FCI) was designed to poll the Newtonian conception of force viewed as a multidimensional concept, that is, as a complex of distinguishable conceptual dimensions. Several previous studies have developed single-trait item response models of FCI data; however, we feel that multidimensional models are also appropriate given the explicitly multidimensional design of the inventory. The models employed in the research reported here vary in both the number of fitting parameters and the number of underlying latent traits assumed. We calculate several model information statistics to ensure adequate model fit and to determine which of the models provides the optimal balance of information and parsimony. Our analysis indicates that all item response models tested, from the single-trait Rasch model through to a model with ten latent traits, satisfy the standard requirements of fit. However, analysis of model information criteria indicates that the five-trait model is optimal. We note that an earlier factor analysis of the same FCI data also led to a five-factor model. Furthermore the factors in our previous study and the traits identified in the current work match each other well. The optimal five-trait model assigns proficiency scores to all respondents for each of the five traits. We construct a correlation matrix between the proficiencies in each of these traits. This correlation matrix shows strong correlations between some proficiencies, and strong anticorrelations between others. We present an interpretation of this correlation matrix.

  6. Murdock free recall data: The initial recall search identifies the context by the location of the least remembered item and produces only better remembered items in proportion to the total recall difference.

    OpenAIRE

    Tarnow, Dr. Eugen

    2009-01-01

    The curious free recall data of Murdock (1962) shows an additional surprise that seems to have gone undetected until now: the probability of guessing an item in the initial recall is not identical to the overall free recall curve. Initial recall of an item is well correlated with the total recall of that item using a straight line but with an unexpected offset. The offset varies with the presentation rate and the total number of list items but in each case it is the same as the total recall ...

  7. A 67-Item Stress Resilience item bank showing high content validity was developed in a psychosomatic sample.

    Science.gov (United States)

    Obbarius, Nina; Fischer, Felix; Obbarius, Alexander; Nolte, Sandra; Liegl, Gregor; Rose, Matthias

    2018-04-10

    To develop the first item bank to measure Stress Resilience (SR) in clinical populations. Qualitative item development resulted in an initial pool of 131 items covering a broad theoretical SR concept. These items were tested in n=521 patients at a psychosomatic outpatient clinic. Exploratory and Confirmatory Factor Analysis (CFA), as well as other state-of-the-art item analyses and IRT were used for item evaluation and calibration of the final item bank. Out of the initial item pool of 131 items, we excluded 64 items (54 factor loading .3, 2 non-discriminative Item Response Curves, 4 Differential Item Functioning). The final set of 67 items indicated sufficient model fit in CFA and IRT analyses. Additionally, a 10-item short form with high measurement precision (SE≤.32 in a theta range between -1.8 and +1.5) was derived. Both the SR item bank and the SR short form were highly correlated with an existing static legacy tool (Connor-Davidson Resilience Scale). The final SR item bank and 10-item short form showed good psychometric properties. When further validated, they will be ready to be used within a framework of Computer-Adaptive Tests for a comprehensive assessment of the Stress-Construct. Copyright © 2018. Published by Elsevier Inc.

  8. Real-time learning of predictive recognition categories that chunk sequences of items stored in working memory

    Directory of Open Access Journals (Sweden)

    Stephen eGrossberg

    2014-10-01

    Full Text Available How are sequences of events that are temporarily stored in a cognitive working memory unitized, or chunked, through learning? Such sequential learning is needed by the brain in order to enable language, spatial understanding, and motor skills to develop. In particular, how does the brain learn categories, or list chunks, that become selectively tuned to different temporal sequences of items in lists of variable length as they are stored in working memory, and how does this learning process occur in real time? The present article introduces a neural model that simulates learning of such list chunks. In this model, sequences of items are temporarily stored in an Item-and-Order, or competitive queuing, working memory before learning categorizes them using a categorization network, called a Masking Field, which is a self-similar, multiple-scale, recurrent on-center off-surround network that can weigh the evidence for variable-length sequences of items as they are stored in the working memory through time. A Masking Field hereby activates the learned list chunks that represent the most predictive item groupings at any time, while suppressing less predictive chunks. In a network with a given number of input items, all possible ordered sets of these item sequences, up to a fixed length, can be learned with unsupervised or supervised learning. The self-similar multiple-scale properties of Masking Fields interacting with an Item-and-Order working memory provide a natural explanation of George Miller's Magical Number Seven and Nelson Cowan's Magical Number Four. The article explains why linguistic, spatial, and action event sequences may all be stored by Item-and-Order working memories that obey similar design principles, and thus how the current results may apply across modalities. Item-and-Order properties may readily be extended to Item-Order-Rank working memories in which the same item can be stored in multiple list positions, or ranks, as in the list

  9. Item difficulty of multiple choice tests dependant on different item response formats – An experiment in fundamental research on psychological assessment

    Directory of Open Access Journals (Sweden)

    KLAUS D. KUBINGER

    2007-12-01

    Full Text Available Multiple choice response formats are problematical as an item is often scored as solved simply because the test-taker is a lucky guesser. Instead of applying pertinent IRT models which take guessing effects into account, a pragmatic approach of re-conceptualizing multiple choice response formats to reduce the chance of lucky guessing is considered. This paper compares the free response format with two different multiple choice formats. A common multiple choice format with a single correct response option and five distractors (“1 of 6” is used, as well as a multiple choice format with five response options, of which any number of the five is correct and the item is only scored as mastered if all the correct response options and none of the wrong ones are marked (“x of 5”. An experiment was designed, using pairs of items with exactly the same content but different response formats. 173 test-takers were randomly assigned to two test booklets of 150 items altogether. Rasch model analyses adduced a fitting item pool, after the deletion of 39 items. The resulting item difficulty parameters were used for the comparison of the different formats. The multiple choice format “1 of 6” differs significantly from “x of 5”, with a relative effect of 1.63, while the multiple choice format “x of 5” does not significantly differ from the free response format. Therefore, the lower degree of difficulty of items with the “1 of 6” multiple choice format is an indicator of relevant guessing effects. In contrast the “x of 5” multiple choice format can be seen as an appropriate substitute for free response format.

  10. Calibration of Automatically Generated Items Using Bayesian Hierarchical Modeling.

    Science.gov (United States)

    Johnson, Matthew S.; Sinharay, Sandip

    For complex educational assessments, there is an increasing use of "item families," which are groups of related items. However, calibration or scoring for such an assessment requires fitting models that take into account the dependence structure inherent among the items that belong to the same item family. C. Glas and W. van der Linden…

  11. Applying Hierarchical Model Calibration to Automatically Generated Items.

    Science.gov (United States)

    Williamson, David M.; Johnson, Matthew S.; Sinharay, Sandip; Bejar, Isaac I.

    This study explored the application of hierarchical model calibration as a means of reducing, if not eliminating, the need for pretesting of automatically generated items from a common item model prior to operational use. Ultimately the successful development of automatic item generation (AIG) systems capable of producing items with highly similar…

  12. 10 CFR 835.605 - Labeling items and containers.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Labeling items and containers. 835.605 Section 835.605... items and containers. Except as provided at § 835.606, each item or container of radioactive material... information to permit individuals handling, using, or working in the vicinity of the items or containers to...

  13. 41 CFR 101-27.404 - Review of items.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true Review of items. 101-27.404 Section 101-27.404 Public Contracts and Property Management Federal Property Management...-Elimination of Items From Inventory § 101-27.404 Review of items. Except for standby or reserve stocks, items...

  14. Australian Chemistry Test Item Bank: Years 11 & 12. Volume 1.

    Science.gov (United States)

    Commons, C., Ed.; Martin, P., Ed.

    Volume 1 of the Australian Chemistry Test Item Bank, consisting of two volumes, contains nearly 2000 multiple-choice items related to the chemistry taught in Year 11 and Year 12 courses in Australia. Items which were written during 1979 and 1980 were initially published in the "ACER Chemistry Test Item Collection" and in the "ACER…

  15. ACER Chemistry Test Item Collection. ACER Chemtic Year 12.

    Science.gov (United States)

    Australian Council for Educational Research, Hawthorn.

    The chemistry test item banks contains 225 multiple-choice questions suitable for diagnostic and achievement testing; a three-page teacher's guide; answer key with item facilities; an answer sheet; and a 45-item sample achievement test. Although written for the new grade 12 chemistry course in Victoria, Australia, the items are widely applicable.…

  16. Utilizing Response Time Distributions for Item Selection in CAT

    Science.gov (United States)

    Fan, Zhewen; Wang, Chun; Chang, Hua-Hua; Douglas, Jeffrey

    2012-01-01

    Traditional methods for item selection in computerized adaptive testing only focus on item information without taking into consideration the time required to answer an item. As a result, some examinees may receive a set of items that take a very long time to finish, and information is not accrued as efficiently as possible. The authors propose two…

  17. A Review of Classical Methods of Item Analysis.

    Science.gov (United States)

    French, Christine L.

    Item analysis is a very important consideration in the test development process. It is a statistical procedure to analyze test items that combines methods used to evaluate the important characteristics of test items, such as difficulty, discrimination, and distractibility of the items in a test. This paper reviews some of the classical methods for…

  18. Methods to Find the Number of Latent Skills

    Science.gov (United States)

    Beheshti, Behzad; Desmarais, Michel C.; Naceur, Rhouma

    2012-01-01

    Identifying the skills that determine the success or failure to exercises and question items is a difficult task. Multiple skills may be involved at various degree of importance, and skills may overlap and correlate. In an effort towards the goal of finding the skills behind a set of items, we investigate two techniques to determine the number of…

  19. U.S. Army Concept of Operations and Standard Operating Procedure for Acquisition Program Managers Using Item Unique Identification

    Science.gov (United States)

    2017-09-01

    a pop up screen will ask to file save as Figure 88. the form on my documents or desktop . Source: Department of the Army (n.d.-e...77 Open the form from desktop or mydocuments in Adobe Acrobat...policy was published as Army Directive 2016–21 in May 2016. Army items requiring serial number management will require IUID. This includes items

  20. Development and Application of Methods for Estimating Operating Characteristics of Discrete Test Item Responses without Assuming any Mathematical Form.

    Science.gov (United States)

    Samejima, Fumiko

    In latent trait theory the latent space, or space of the hypothetical construct, is usually represented by some unidimensional or multi-dimensional continuum of real numbers. Like the latent space, the item response can either be treated as a discrete variable or as a continuous variable. Latent trait theory relates the item response to the latent…

  1. Incorporation of an item/material attribute system into PAMTRAK

    International Nuclear Information System (INIS)

    Anspach, D.A.; Waddoups, I.G.; Fox, E.T.

    1994-01-01

    The Department of Energy (DOE) mission is changing due to the number of nuclear weapon reductions by the United States and the former Soviet Union with long-term storage requirements for DOE sites increasing. New technology to ensure the integrity of special nuclear material (SNM) in storage is available to sites to supplement manual physical inventories. This allows them to decrease operating costs while keeping radiation exposure at minimal levels. We have developed a generic, real time, personnel tracking and material monitoring system named PAMTRAK. Such a system can significantly reduce the number of required, manual physical inventories at DOE sites while increasing assurance that an insider has not diverted or stolen material. Until recently Pamtrak used only material monitoring devices that provided location/containment attributes. However, Westinghouse Electric Corp. and Metrox, Inc. have recently developed hard-wired item/material attribute systems that monitor both temperature and weight. We have incorporated both of these systems into PAMTRAK. If a site employed one of these item/material attribute systems, it could decrease its manual inventory frequency to three years. This paper describes how a site might implement such a system to meet the DOE's requirements

  2. Item analysis and evaluation in the examinations in the faculty of ...

    African Journals Online (AJOL)

    2014-11-05

    Nov 5, 2014 ... Key words: Classical test theory, item analysis, item difficulty, item discrimination, item response theory, reliability ... the probability of answering an item correctly or of attaining ..... A Monte Carlo comparison of item and person.

  3. Development of the Open Items Tracking System

    International Nuclear Information System (INIS)

    Riggi, V.

    1994-01-01

    The West Valley Demonstration Project, located on the site of the only commercial nuclear fuel reprocessing facility to have operated in USA, has the directed objectives of solidifying the high-level radioactive waste into a durable, solid form for shipment; decontaminating and decommissioning the tanks and facilities; and disposing of the resulting low-level and transuranic wastes. Since an escalating trend of open work items was noticed in the Fall of 1988, and there was no control mechanism for tracking and closing the open items, a Work Control System was developed for this purpose. It is self-contained system on a mainframe ARTEMIS 9000, which tracks, monitors, and closes out external commitments in a timely manner. Audits, surveillances, site appraisals, preventive maintenance, instrument calibration recall, and scheduling are covered

  4. Item calibration in incomplete testing designs

    Directory of Open Access Journals (Sweden)

    Norman D. Verhelst

    2011-01-01

    Full Text Available This study discusses the justifiability of item parameter estimation in incomplete testing designs in item response theory. Marginal maximum likelihood (MML as well as conditional maximum likelihood (CML procedures are considered in three commonly used incomplete designs: random incomplete, multistage testing and targeted testing designs. Mislevy and Sheenan (1989 have shown that in incomplete designs the justifiability of MML can be deduced from Rubin's (1976 general theory on inference in the presence of missing data. Their results are recapitulated and extended for more situations. In this study it is shown that for CML estimation the justification must be established in an alternative way, by considering the neglected part of the complete likelihood. The problems with incomplete designs are not generally recognized in practical situations. This is due to the stochastic nature of the incomplete designs which is not taken into account in standard computer algorithms. For that reason, incorrect uses of standard MML- and CML-algorithms are discussed.

  5. Effect of study context on item recollection.

    Science.gov (United States)

    Skinner, Erin I; Fernandes, Myra A

    2010-07-01

    We examined how visual context information provided during encoding, and unrelated to the target word, affected later recollection for words presented alone using a remember-know paradigm. Experiments 1A and 1B showed that participants had better overall memory-specifically, recollection-for words studied with pictures of intact faces than for words studied with pictures of scrambled or inverted faces. Experiment 2 replicated these results and showed that recollection was higher for words studied with pictures of faces than when no image accompanied the study word. In Experiment 3 participants showed equivalent memory for words studied with unique faces as for those studied with a repeatedly presented face. Results suggest that recollection benefits when visual context information high in meaningful content accompanies study words and that this benefit is not related to the uniqueness of the context. We suggest that participants use elaborative processes to integrate item and meaningful contexts into ensemble information, improving subsequent item recollection.

  6. An evaluation of computerized adaptive testing for general psychological distress: combining GHQ-12 and Affectometer-2 in an item bank for public mental health research.

    Science.gov (United States)

    Stochl, Jan; Böhnke, Jan R; Pickett, Kate E; Croudace, Tim J

    2016-05-20

    Recent developments in psychometric modeling and technology allow pooling well-validated items from existing instruments into larger item banks and their deployment through methods of computerized adaptive testing (CAT). Use of item response theory-based bifactor methods and integrative data analysis overcomes barriers in cross-instrument comparison. This paper presents the joint calibration of an item bank for researchers keen to investigate population variations in general psychological distress (GPD). Multidimensional item response theory was used on existing health survey data from the Scottish Health Education Population Survey (n = 766) to calibrate an item bank consisting of pooled items from the short common mental disorder screen (GHQ-12) and the Affectometer-2 (a measure of "general happiness"). Computer simulation was used to evaluate usefulness and efficacy of its adaptive administration. A bifactor model capturing variation across a continuum of population distress (while controlling for artefacts due to item wording) was supported. The numbers of items for different required reliabilities in adaptive administration demonstrated promising efficacy of the proposed item bank. Psychometric modeling of the common dimension captured by more than one instrument offers the potential of adaptive testing for GPD using individually sequenced combinations of existing survey items. The potential for linking other item sets with alternative candidate measures of positive mental health is discussed since an optimal item bank may require even more items than these.

  7. Selection of multiple cued items is possible during visual short-term memory maintenance.

    Science.gov (United States)

    Matsukura, Michi; Vecera, Shaun P

    2015-07-01

    Recent neuroimaging studies suggest that maintenance of a selected object feature held in visual short-term/working memory (VSTM/VWM) is supported by the same neural mechanisms that encode the sensory information. If VSTM operates by retaining "reasonable copies" of scenes constructed during sensory processing (Serences, Ester, Vogel, & Awh, 2009, p. 207, the sensory recruitment hypothesis), then attention should be able to select multiple items represented in VSTM as long as the number of these attended items does not exceed the typical VSTM capacity. It is well known that attention can select at least two noncontiguous locations at the same time during sensory processing. However, empirical reports from the studies that examined this possibility are inconsistent. In the present study, we demonstrate that (1) attention can indeed select more than a single item during VSTM maintenance when observers are asked to recognize a set of items in the manner that these items were originally attended, and (2) attention can select multiple cued items regardless of whether these items are perceptually organized into a single group (contiguous locations) or not (noncontiguous locations). The results also replicate and extend the recent finding that selective attention that operates during VSTM maintenance is sensitive to the observers' goal and motivation to use the cueing information.

  8. Differential item functioning analysis of the Vanderbilt Expertise Test for cars.

    Science.gov (United States)

    Lee, Woo-Yeol; Cho, Sun-Joo; McGugin, Rankin W; Van Gulick, Ana Beth; Gauthier, Isabel

    2015-01-01

    The Vanderbilt Expertise Test for cars (VETcar) is a test of visual learning for contemporary car models. We used item response theory to assess the VETcar and in particular used differential item functioning (DIF) analysis to ask if the test functions the same way in laboratory versus online settings and for different groups based on age and gender. An exploratory factor analysis found evidence of multidimensionality in the VETcar, although a single dimension was deemed sufficient to capture the recognition ability measured by the test. We selected a unidimensional three-parameter logistic item response model to examine item characteristics and subject abilities. The VETcar had satisfactory internal consistency. A substantial number of items showed DIF at a medium effect size for test setting and for age group, whereas gender DIF was negligible. Because online subjects were on average older than those tested in the lab, we focused on the age groups to conduct a multigroup item response theory analysis. This revealed that most items on the test favored the younger group. DIF could be more the rule than the exception when measuring performance with familiar object categories, therefore posing a challenge for the measurement of either domain-general visual abilities or category-specific knowledge.

  9. The impact of item order on ratings of cancer risk perception.

    Science.gov (United States)

    Taylor, Kathryn L; Shelby, Rebecca A; Schwartz, Marc D; Ackerman, Josh; LaSalle, V Holland; Gelmann, Edward P; McGuire, Colleen

    2002-07-01

    Although perceived risk is central to most theories of health behavior, there is little consensus on its measurement with regard to item wording, response set, or the number of items to include. In a methodological assessment of perceived risk, we assessed the impact of changing the order of three commonly used perceived risk items: quantitative personal risk, quantitative population risk, and comparative risk. Participants were 432 men and women enrolled in an ancillary study of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Three groups of consecutively enrolled participants responded to the three items in one of three question orders. Results indicated that item order was related to the perceived risk ratings of both ovarian (P Perceptions of risk were significantly lower when the comparative rating was made first. The findings suggest that compelling participants to consider their own risk relative to the risk of others results in lower ratings of perceived risk. Although the use of multiple items may provide more information than when only a single method is used, different conclusions may be reached depending on the context in which an item is assessed.

  10. K-12 Literacy. Where We Stand. Item Number 39-0231

    Science.gov (United States)

    American Federation of Teachers, 2007

    2007-01-01

    This document contains texts for two resolutions adopted by the American Federation of Teachers (AFT) in July 1998 regarding Beginning Reading Instruction and in July 2006, regarding Adolescent Literacy. A Question & Answer section follows the resolutions, addressing the following issues: (1) Reasons for focus on reading; (2) Differing views on…

  11. Redesigning Schools to Raise Achievement. Where We Stand. Item Number 39-0232

    Science.gov (United States)

    American Federation of Teachers, 2006

    2006-01-01

    This document contains resolution text adopted by the American Federation of Teachers (AFT) in July 1998 regarding Redesigning Low-Performing Schools. A Question & Answer section follows the resolution, addressing the following issues: (1) Union support for redesign or closure of low-performing schools; (2) Indicators of low-performing schools…

  12. Fighting for the Profession: A History of AFT Higher Education. Item Number 36-0701

    Science.gov (United States)

    American Federation of Teachers, 2003

    2003-01-01

    This document provides a history of the relationship between higher education faculty and the American Federation of Teachers (AFT). Highlights include the first AFT higher education local formed in 1918, the role played by the union in the expansion of the G.I. Bill following World War II, increased activism in the 1950s and 1960s to win…

  13. English Language Learners. Where We Stand. Item Number 39-0247

    Science.gov (United States)

    American Federation of Teachers, 2006

    2006-01-01

    This document contains resolution text adopted by the American Federation of Teachers (AFT) in July 2006 regarding English language learners (ELLs). A Question & Answer section follows the resolution, addressing the following issues: (1) How the AFT is helping educators who work with ELLs; (2) Latest research on effective literacy practices for…

  14. 17 CFR 260.7a-16 - Inclusion of items, differentiation between items and answers, omission of instructions.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Inclusion of items, differentiation between items and answers, omission of instructions. 260.7a-16 Section 260.7a-16 Commodity and... INDENTURE ACT OF 1939 Formal Requirements § 260.7a-16 Inclusion of items, differentiation between items and...

  15. Dissociating the neural correlates of intra-item and inter-item working-memory binding.

    Directory of Open Access Journals (Sweden)

    Carinne Piekema

    Full Text Available BACKGROUND: Integration of information streams into a unitary representation is an important task of our cognitive system. Within working memory, the medial temporal lobe (MTL has been conceptually linked to the maintenance of bound representations. In a previous fMRI study, we have shown that the MTL is indeed more active during working-memory maintenance of spatial associations as compared to non-spatial associations or single items. There are two explanations for this result, the mere presence of the spatial component activates the MTL, or the MTL is recruited to bind associations between neurally non-overlapping representations. METHODOLOGY/PRINCIPAL FINDINGS: The current fMRI study investigates this issue further by directly comparing intrinsic intra-item binding (object/colour, extrinsic intra-item binding (object/location, and inter-item binding (object/object. The three binding conditions resulted in differential activation of brain regions. Specifically, we show that the MTL is important for establishing extrinsic intra-item associations and inter-item associations, in line with the notion that binding of information processed in different brain regions depends on the MTL. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that different forms of working-memory binding rely on specific neural structures. In addition, these results extend previous reports indicating that the MTL is implicated in working-memory maintenance, challenging the classic distinction between short-term and long-term memory systems.

  16. Development of abbreviated eight-item form of the Penn Verbal Reasoning Test.

    Science.gov (United States)

    Bilker, Warren B; Wierzbicki, Michael R; Brensinger, Colleen M; Gur, Raquel E; Gur, Ruben C

    2014-12-01

    The ability to reason with language is a highly valued cognitive capacity that correlates with IQ measures and is sensitive to damage in language areas. The Penn Verbal Reasoning Test (PVRT) is a 29-item computerized test for measuring abstract analogical reasoning abilities using language. The full test can take over half an hour to administer, which limits its applicability in large-scale studies. We previously described a procedure for abbreviating a clinical rating scale and a modified procedure for reducing tests with a large number of items. Here we describe the application of the modified method to reducing the number of items in the PVRT to a parsimonious subset of items that accurately predicts the total score. As in our previous reduction studies, a split sample is used for model fitting and validation, with cross-validation to verify results. We find that an 8-item scale predicts the total 29-item score well, achieving a correlation of .9145 for the reduced form for the model fitting sample and .8952 for the validation sample. The results indicate that a drastically abbreviated version, which cuts administration time by more than 70%, can be safely administered as a predictor of PVRT performance. © The Author(s) 2014.

  17. Development of Abbreviated Eight-Item Form of the Penn Verbal Reasoning Test

    Science.gov (United States)

    Bilker, Warren B.; Wierzbicki, Michael R.; Brensinger, Colleen M.; Gur, Raquel E.; Gur, Ruben C.

    2014-01-01

    The ability to reason with language is a highly valued cognitive capacity that correlates with IQ measures and is sensitive to damage in language areas. The Penn Verbal Reasoning Test (PVRT) is a 29-item computerized test for measuring abstract analogical reasoning abilities using language. The full test can take over half an hour to administer, which limits its applicability in large-scale studies. We previously described a procedure for abbreviating a clinical rating scale and a modified procedure for reducing tests with a large number of items. Here we describe the application of the modified method to reducing the number of items in the PVRT to a parsimonious subset of items that accurately predicts the total score. As in our previous reduction studies, a split sample is used for model fitting and validation, with cross-validation to verify results. We find that an 8-item scale predicts the total 29-item score well, achieving a correlation of .9145 for the reduced form for the model fitting sample and .8952 for the validation sample. The results indicate that a drastically abbreviated version, which cuts administration time by more than 70%, can be safely administered as a predictor of PVRT performance. PMID:24577310

  18. Language and number: a bilingual training study.

    Science.gov (United States)

    Spelke, E S; Tsivkin, S

    2001-01-01

    Three experiments investigated the role of a specific language in human representations of number. Russian-English bilingual college students were taught new numerical operations (Experiment 1), new arithmetic equations (Experiments 1 and 2), or new geographical or historical facts involving numerical or non-numerical information (Experiment 3). After learning a set of items in each of their two languages, subjects were tested for knowledge of those items, and new items, in both languages. In all the studies, subjects retrieved information about exact numbers more effectively in the language of training, and they solved trained problems more effectively than untrained problems. In contrast, subjects retrieved information about approximate numbers and non-numerical facts with equal efficiency in their two languages, and their training on approximate number facts generalized to new facts of the same type. These findings suggest that a specific, natural language contributes to the representation of large, exact numbers but not to the approximate number representations that humans share with other mammals. Language appears to play a role in learning about exact numbers in a variety of contexts, a finding with implications for practice in bilingual education. The findings prompt more general speculations about the role of language in the development of specifically human cognitive abilities.

  19. Measuring everyday functional competence using the Rasch assessment of everyday activity limitations (REAL) item bank.

    Science.gov (United States)

    Oude Voshaar, Martijn A H; Ten Klooster, Peter M; Vonkeman, Harald E; van de Laar, Mart A F J

    2017-11-01

    Traditional patient-reported physical function instruments often poorly differentiate patients with mild-to-moderate disability. We describe the development and psychometric evaluation of a generic item bank for measuring everyday activity limitations in outpatient populations. Seventy-two items generated from patient interviews and mapped to the International Classification of Functioning, Disability and Health (ICF) domestic life chapter were administered to 1128 adults representative of the Dutch population. The partial credit model was fitted to the item responses and evaluated with respect to its assumptions, model fit, and differential item functioning (DIF). Measurement performance of a computerized adaptive testing (CAT) algorithm was compared with the SF-36 physical functioning scale (PF-10). A final bank of 41 items was developed. All items demonstrated acceptable fit to the partial credit model and measurement invariance across age, sex, and educational level. Five- and ten-item CAT simulations were shown to have high measurement precision, which exceeded that of SF-36 physical functioning scale across the physical function continuum. Floor effects were absent for a 10-item empirical CAT simulation, and ceiling effects were low (13.5%) compared with SF-36 physical functioning (38.1%). CAT also discriminated better than SF-36 physical functioning between age groups, number of chronic conditions, and respondents with or without rheumatic conditions. The Rasch assessment of everyday activity limitations (REAL) item bank will hopefully prove a useful instrument for assessing everyday activity limitations. T-scores obtained using derived measures can be used to benchmark physical function outcomes against the general Dutch adult population.

  20. The quadratic relationship between difficulty of intelligence test items and their correlations with working memory

    Directory of Open Access Journals (Sweden)

    Tomasz eSmoleń

    2015-08-01

    Full Text Available Fluid intelligence (Gf is a crucial cognitive ability that involves abstract reasoning in order to solve novel problems. Recent research demonstrated that Gf strongly depends on the individual effectiveness of working memory (WM. We investigated a popular claim that if the storage capacity underlay the WM-Gf correlation, then such a correlation should increase with an increasing number of items or rules (load in a Gf test. As often no such link is observed, on that basis the storage-capacity account is rejected, and alternative accounts of Gf (e.g., related to executive control or processing speed are proposed. Using both analytical inference and numerical simulations, we demonstrated that the load-dependent change in correlation is primarily a function of the amount of floor/ceiling effect for particular items. Thus, the item-wise WM correlation of a Gf test depends on its overall difficulty, and the difficulty distribution across its items. When the early test items yield huge ceiling, but the late items do not approach floor, that correlation will increase throughout the test. If the early items locate themselves between ceiling and floor, but the late items approach floor, the respective correlation will decrease. For a hallmark Gf test, the Raven test, whose items span from ceiling to floor, the quadratic relationship is expected, and it was shown empirically using a large sample and two types of WMC tasks. In consequence, no changes in correlation due to varying WM/Gf load, or lack of them, can yield an argument for or against any theory of WM/Gf. Moreover, as the mathematical properties of the correlation formula make it relatively immune to ceiling/floor effects for overall moderate correlations, only minor changes (if any in the WM-Gf correlation should be expected for many psychological tests.

  1. The quadratic relationship between difficulty of intelligence test items and their correlations with working memory.

    Science.gov (United States)

    Smolen, Tomasz; Chuderski, Adam

    2015-01-01

    Fluid intelligence (Gf) is a crucial cognitive ability that involves abstract reasoning in order to solve novel problems. Recent research demonstrated that Gf strongly depends on the individual effectiveness of working memory (WM). We investigated a popular claim that if the storage capacity underlay the WM-Gf correlation, then such a correlation should increase with an increasing number of items or rules (load) in a Gf-test. As often no such link is observed, on that basis the storage-capacity account is rejected, and alternative accounts of Gf (e.g., related to executive control or processing speed) are proposed. Using both analytical inference and numerical simulations, we demonstrated that the load-dependent change in correlation is primarily a function of the amount of floor/ceiling effect for particular items. Thus, the item-wise WM correlation of a Gf-test depends on its overall difficulty, and the difficulty distribution across its items. When the early test items yield huge ceiling, but the late items do not approach floor, that correlation will increase throughout the test. If the early items locate themselves between ceiling and floor, but the late items approach floor, the respective correlation will decrease. For a hallmark Gf-test, the Raven-test, whose items span from ceiling to floor, the quadratic relationship is expected, and it was shown empirically using a large sample and two types of WMC tasks. In consequence, no changes in correlation due to varying WM/Gf load, or lack of them, can yield an argument for or against any theory of WM/Gf. Moreover, as the mathematical properties of the correlation formula make it relatively immune to ceiling/floor effects for overall moderate correlations, only minor changes (if any) in the WM-Gf correlation should be expected for many psychological tests.

  2. CTTITEM: SAS macro and SPSS syntax for classical item analysis.

    Science.gov (United States)

    Lei, Pui-Wa; Wu, Qiong

    2007-08-01

    This article describes the functions of a SAS macro and an SPSS syntax that produce common statistics for conventional item analysis including Cronbach's alpha, item difficulty index (p-value or item mean), and item discrimination indices (D-index, point biserial and biserial correlations for dichotomous items and item-total correlation for polytomous items). These programs represent an improvement over the existing SAS and SPSS item analysis routines in terms of completeness and user-friendliness. To promote routine evaluations of item qualities in instrument development of any scale, the programs are available at no charge for interested users. The program codes along with a brief user's manual that contains instructions and examples are downloadable from suen.ed.psu.edu/-pwlei/plei.htm.

  3. CAT-ASVAB Technical Bulletin Number 1

    Science.gov (United States)

    2006-03-01

    CAT -ASVAB Technical Bulletin #1 Personnel Testing Division Defense Manpower Data Center March 2006 Report...2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE CAT -ASVAB Technical Bulletin #1 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...Hetter, R. D. "Psychometric Procedures for Administering CAT -ASVAB" (pp. 131-140) Chapter 4 Hetter, R. D., & Sympson J. B. "Item Exposure

  4. Pengendalian Persediaan Primary Items dalam Logistik Konstruksi

    Directory of Open Access Journals (Sweden)

    Lady Lisya

    2016-09-01

    Full Text Available Construction logistics are activities that consist of ordering, storage and transportation of materials of construction projects. Storage material is logistics activity that ensure the availability of materials in project site. Generally, material storage activities have been conducted at the project site. Logistics construction is aimed to support the project activities that the completion schedule has been set. Construction logistics issues is determining the schedule of ordering materials so that the project can be implemented on schedule. The purpose of research is to determine the optimum ordering period for the primary items on the main building structure construction and designing inventory control cards as a mechanism for monitoring procurement of materials. This research has been obtained optimal ordering period for the primary items of main building structure with elements of the work using Fixed Period Requirement method. Inventories were already meet the material requirement of each period. Material management has been conducted based grouping approach as many as 31 groups. In addition, this research has proposed the inventory control cards as an instrument for material procurement monitoring. The implications of inventory control cards are coordinate contracting parties with vendors to plan the replenishment  of materials to meet the work schedule. Further research can be developed with other aspects such as integrated material order system between contractors and vendors to consider the safety stock. In addition, the information system for planning material is an important consideration for construction projects with large scale so that the companies can plan primary items inventory and other materials in the projects completion more easily, quickly and accurately.

  5. Reliability and validity of the Spanish version of the 10-item Connor-Davidson Resilience Scale (10-item CD-RISC in young adults

    Directory of Open Access Journals (Sweden)

    García-Campayo Javier

    2011-08-01

    Full Text Available Abstract Background The 10-item Connor-Davidson Resilience Scale (10-item CD-RISC is an instrument for measuring resilience that has shown good psychometric properties in its original version in English. The aim of this study was to evaluate the validity and reliability of the Spanish version of the 10-item CD-RISC in young adults and to verify whether it is structured in a single dimension as in the original English version. Findings Cross-sectional observational study including 681 university students ranging in age from 18 to 30 years. The number of latent factors in the 10 items of the scale was analyzed by exploratory factor analysis. Confirmatory factor analysis was used to verify whether a single factor underlies the 10 items of the scale as in the original version in English. The convergent validity was analyzed by testing whether the mean of the scores of the mental component of SF-12 (MCS and the quality of sleep as measured with the Pittsburgh Sleep Index (PSQI were higher in subjects with better levels of resilience. The internal consistency of the 10-item CD-RISC was estimated using the Cronbach α test and test-retest reliability was estimated with the intraclass correlation coefficient. The Cronbach α coefficient was 0.85 and the test-retest intraclass correlation coefficient was 0.71. The mean MCS score and the level of quality of sleep in both men and women were significantly worse in subjects with lower resilience scores. Conclusions The Spanish version of the 10-item CD-RISC showed good psychometric properties in young adults and thus can be used as a reliable and valid instrument for measuring resilience. Our study confirmed that a single factor underlies the resilience construct, as was the case of the original scale in English.

  6. A review of the effects on IRT item parameter estimates with a focus on misbehaving common items in test equating

    Directory of Open Access Journals (Sweden)

    Michalis P Michaelides

    2010-10-01

    Full Text Available Many studies have investigated the topic of change or drift in item parameter estimates in the context of Item Response Theory. Content effects, such as instructional variation and curricular emphasis, as well as context effects, such as the wording, position, or exposure of an item have been found to impact item parameter estimates. The issue becomes more critical when items with estimates exhibiting differential behavior across test administrations are used as common for deriving equating transformations. This paper reviews the types of effects on IRT item parameter estimates and focuses on the impact of misbehaving or aberrant common items on equating transformations. Implications relating to test validity and the judgmental nature of the decision to keep or discard aberrant common items are discussed, with recommendations for future research into more informed and formal ways of dealing with misbehaving common items.

  7. A Review of the Effects on IRT Item Parameter Estimates with a Focus on Misbehaving Common Items in Test Equating.

    Science.gov (United States)

    Michaelides, Michalis P

    2010-01-01

    Many studies have investigated the topic of change or drift in item parameter estimates in the context of item response theory (IRT). Content effects, such as instructional variation and curricular emphasis, as well as context effects, such as the wording, position, or exposure of an item have been found to impact item parameter estimates. The issue becomes more critical when items with estimates exhibiting differential behavior across test administrations are used as common for deriving equating transformations. This paper reviews the types of effects on IRT item parameter estimates and focuses on the impact of misbehaving or aberrant common items on equating transformations. Implications relating to test validity and the judgmental nature of the decision to keep or discard aberrant common items are discussed, with recommendations for future research into more informed and formal ways of dealing with misbehaving common items.

  8. Number Sense on the Number Line

    Science.gov (United States)

    Woods, Dawn Marie; Ketterlin Geller, Leanne; Basaraba, Deni

    2018-01-01

    A strong foundation in early number concepts is critical for students' future success in mathematics. Research suggests that visual representations, like a number line, support students' development of number sense by helping them create a mental representation of the order and magnitude of numbers. In addition, explicitly sequencing instruction…

  9. Holding Multiple Items in Short Term Memory: A Neural Mechanism

    Science.gov (United States)

    Rolls, Edmund T.; Dempere-Marco, Laura; Deco, Gustavo

    2013-01-01

    Human short term memory has a capacity of several items maintained simultaneously. We show how the number of short term memory representations that an attractor network modeling a cortical local network can simultaneously maintain active is increased by using synaptic facilitation of the type found in the prefrontal cortex. We have been able to maintain 9 short term memories active simultaneously in integrate-and-fire simulations where the proportion of neurons in each population, the sparseness, is 0.1, and have confirmed the stability of such a system with mean field analyses. Without synaptic facilitation the system can maintain many fewer memories active in the same network. The system operates because of the effectively increased synaptic strengths formed by the synaptic facilitation just for those pools to which the cue is applied, and then maintenance of this synaptic facilitation in just those pools when the cue is removed by the continuing neuronal firing in those pools. The findings have implications for understanding how several items can be maintained simultaneously in short term memory, how this may be relevant to the implementation of language in the brain, and suggest new approaches to understanding and treating the decline in short term memory that can occur with normal aging. PMID:23613789

  10. Household income differences in food sources and food items purchased.

    Science.gov (United States)

    French, Simone A; Wall, Melanie; Mitchell, Nathan R

    2010-10-26

    The present study examined income-related household food purchases among a sample of 90 households from the community. Annotated food purchase receipts were collected for a four-week period by the primary household shopper. Receipt food source and foods items were classified into specific categories, and food quantities in ounces were recorded by research staff. For home sources, a limited number of food/beverage categories were recorded. For eating out sources, all food/beverage items were recorded. Median monthly per person dollars spent and per person ounces purchased were computed. Food sources and food categories were examined by household income tertile. A community-based sample of 90 households. Higher income households spent significantly more dollars per person per month from both home and eating out sources compared with lower income households ($163 versus $100, p income households, higher income households spent significantly more home source dollars on both fruits/vegetables (21.5 versus 10.2, p income households (45% versus 26%, p sources, lower income households spent a significantly greater percent of dollars per person at carry out places (54% versus 37%, p income differences were observed for dollars spent at discount grocery stores, small grocery stores or convenience stores. Higher income households spent more money on both healthy and less healthy foods from a wide range of sources. Lower income households spent a larger proportion of their eating out dollars at carry out places, and a larger proportion of their home beverage purchases were sugar sweetened beverages.

  11. Holding multiple items in short term memory: a neural mechanism.

    Directory of Open Access Journals (Sweden)

    Edmund T Rolls

    Full Text Available Human short term memory has a capacity of several items maintained simultaneously. We show how the number of short term memory representations that an attractor network modeling a cortical local network can simultaneously maintain active is increased by using synaptic facilitation of the type found in the prefrontal cortex. We have been able to maintain 9 short term memories active simultaneously in integrate-and-fire simulations where the proportion of neurons in each population, the sparseness, is 0.1, and have confirmed the stability of such a system with mean field analyses. Without synaptic facilitation the system can maintain many fewer memories active in the same network. The system operates because of the effectively increased synaptic strengths formed by the synaptic facilitation just for those pools to which the cue is applied, and then maintenance of this synaptic facilitation in just those pools when the cue is removed by the continuing neuronal firing in those pools. The findings have implications for understanding how several items can be maintained simultaneously in short term memory, how this may be relevant to the implementation of language in the brain, and suggest new approaches to understanding and treating the decline in short term memory that can occur with normal aging.

  12. Holding multiple items in short term memory: a neural mechanism.

    Science.gov (United States)

    Rolls, Edmund T; Dempere-Marco, Laura; Deco, Gustavo

    2013-01-01

    Human short term memory has a capacity of several items maintained simultaneously. We show how the number of short term memory representations that an attractor network modeling a cortical local network can simultaneously maintain active is increased by using synaptic facilitation of the type found in the prefrontal cortex. We have been able to maintain 9 short term memories active simultaneously in integrate-and-fire simulations where the proportion of neurons in each population, the sparseness, is 0.1, and have confirmed the stability of such a system with mean field analyses. Without synaptic facilitation the system can maintain many fewer memories active in the same network. The system operates because of the effectively increased synaptic strengths formed by the synaptic facilitation just for those pools to which the cue is applied, and then maintenance of this synaptic facilitation in just those pools when the cue is removed by the continuing neuronal firing in those pools. The findings have implications for understanding how several items can be maintained simultaneously in short term memory, how this may be relevant to the implementation of language in the brain, and suggest new approaches to understanding and treating the decline in short term memory that can occur with normal aging.

  13. The Super Patalan Numbers

    OpenAIRE

    Richardson, Thomas M.

    2014-01-01

    We introduce the super Patalan numbers, a generalization of the super Catalan numbers in the sense of Gessel, and prove a number of properties analagous to those of the super Catalan numbers. The super Patalan numbers generalize the super Catalan numbers similarly to how the Patalan numbers generalize the Catalan numbers.

  14. Common data items in seven European oesophagogastric cancer surgery registries: towards a European upper GI cancer audit (EURECCA Upper GI).

    Science.gov (United States)

    de Steur, W O; Henneman, D; Allum, W H; Dikken, J L; van Sandick, J W; Reynolds, J; Mariette, C; Jensen, L; Johansson, J; Kolodziejczyk, P; Hardwick, R H; van de Velde, C J H

    2014-03-01

    Seven countries (Denmark, France, Ireland, the Netherlands, Poland, Sweden, United Kingdom) collaborated to initiate a EURECCA (European Registration of Cancer Care) Upper GI project. The aim of this study was to identify a core dataset of shared items in the different data registries which can be used for future collaboration between countries. Item lists from all participating Upper GI cancer registries were collected. Items were scored 'present' when included in the registry, or when the items could be deducted from other items in the registry. The definition of a common item was that it was present in at least six of the seven participating countries. The number of registered items varied between 40 (Poland) and 650 (Ireland). Among the 46 shared items were data on patient characteristics, staging and diagnostics, neoadjuvant treatment, surgery, postoperative course, pathology, and adjuvant treatment. Information on non-surgical treatment was available in only 4 registries. A list of 46 shared items from seven participating Upper GI cancer registries was created, providing a basis for future quality assurance and research in Upper GI cancer treatment on a European level. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Cash Impact of the Consumable Item Transfer, Phase II

    National Research Council Canada - National Science Library

    1998-01-01

    ...). This report is the third in a series of reports regarding the consumable item transfer (CIT), phase II. The Deputy Secretary of Defense directed the transfer of the management of consumable items to Defense Logistics Agency...

  16. Negative affect impairs associative memory but not item memory.

    OpenAIRE

    Bisby, J. A.; Burgess, N.

    2014-01-01

    The formation of associations between items and their context has been proposed to rely on mechanisms distinct from those supporting memory for a single item. Although emotional experiences can profoundly affect memory, our understanding of how it interacts with different aspects of memory remains unclear. We performed three experiments to examine the effects of emotion on memory for items and their associations. By presenting neutral and negative items with background contexts, Experiment 1 ...

  17. 26 CFR 301.6501(o)-3 - Partnership items.

    Science.gov (United States)

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Partnership items. 301.6501(o)-3 Section 301... § 301.6501(o)-3 Partnership items. (a) Partnership item defined. For purposes of section 6501(o) (as it..., and § 301.6511(g)-1, the term “partnership item” means— (1) Any item required to be taken into account...

  18. On multidimensional item response theory -- a coordinate free approach

    OpenAIRE

    Antal, Tamás

    2007-01-01

    A coordinate system free definition of complex structure multidimensional item response theory (MIRT) for dichotomously scored items is presented. The point of view taken emphasizes the possibilities and subtleties of understanding MIRT as a multidimensional extension of the ``classical'' unidimensional item response theory models. The main theorem of the paper is that every monotonic MIRT model looks the same; they are all trivial extensions of univariate item response theory.

  19. Ten Items of Integrated Technology Developed by CNPC

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ The technological work of China National Petroleum Corporation (CNPC) was based on the company's general development strategy to become a multinational giant with international competitiveness during the 10th FiveYear Plan Period (2001-2005). The technological efforts were focused on strengthening strategic management of technology to identify the technological development targets, optimizing allocation of technological resources and increasing technological investment to highlight creation of key technology. Aiming at the important and key technologies needed for main business development,CNPC launched 15 technological projects at the State level with a 100 percent completion rate and 379 other projects at the corporate level with a 92.8 percent completion rate. With a number of high-level results achieved, CNPC has developed 10 items of integrated technology.

  20. Borrowing and Loan Words: The Lemmatizing of Newly Acquired Lexical Items in Sesotho sa Leboa

    Directory of Open Access Journals (Sweden)

    V.M. Mojela

    2011-10-01

    Full Text Available

    ABSTRACT: The influence of foreign languages in Sesotho sa Leboa, or Northern Sotho, results in borrowing, which ultimately leads to an increase in the vocabulary of Sesotho sa Leboa. The languages influencing developments in the vocabulary of Sesotho sa Leboa include, inter alia, English, Afrikaans, Xitsonga, Tshivend√a and the Nguni languages. This article aims to give a critical analysis of the advantages and disadvantages of the adoption of foreign lexical items in the lemmatization of vocabulary in Sesotho sa Leboa dictionaries. Most puristic inclined academics and intellectuals are reluctant to adopt loan words as a means of developing the Sesotho sa Leboa vocabulary. When confronted with borrowing, the purists usually prefer coinage, using indigenous lexical items to name foreign concepts. This is disadvantageous to the development of the vocabulary of the language because (1 there is no increase in the number of the lexical items in the language since only the meanings of the foreign lexical item are added to existing indigenous lexical items, and (2 in most cases, previously adopted loan words are mistaken for indigenous lexical items and given preference to newly acquired lexical items which have direct and accurate bearing on the meaning of the newly discovered or designed concepts or objects.

    OPSOMMING: Ontlening en leenwoorde: Die lemmatisering van nuutverworwe leksikale items in Sesotho sa Leboa. Die invloed van vreemde tale op Sesotho sa Leboa, of Noord-Sotho, het ontlening tot gevolg, wat uiteindelik lei tot 'n toename in die woordeskat van Sesotho sa Leboa. Die tale wat ontwikkelinge in die woordeskat van Sesotho sa Leboa beïnvloed, sluit onder andere Engels, Afrikaans, Xitsonga, Tsivend√a en die Ngunitale in. Die doel van hierdie artikel is om 'n kritiese ontleding van die voordele en nadele van die oorneem van vreemde leksikale items by die lemmatisering van die woordeskat in woordeboeke van Sesotho sa Leboa te

  1. Smaller food item sizes of snack foods influence reduced portions and caloric intake in young adults.

    Science.gov (United States)

    Marchiori, David; Waroquier, Laurent; Klein, Olivier

    2011-05-01

    Studies considering the impact of food-size variations on consumption have predominantly focused on portion size, whereas very little research has investigated variations in food-item size, especially at snacking occasions, and results have been contradictory. This study evaluated the effect of altering the size of food items (ie, small vs large candies) of equal-size food portions on short-term energy intake while snacking. The study used a between-subjects design (n=33) in a randomized experiment conducted in spring 2008. In a psychology laboratory (separate cubicles), participants (undergraduate psychology students, 29 of 33 female, mean age 20.3±2 years, mean body mass index 21.7±3.7) were offered unlimited consumption of candies while participating in an unrelated computerized experiment. For half of the subjects, items were cut in two to make the small food-item size. Food intake (weight in grams, kilocalories, and number of food items) was examined using analysis of variance. Results showed that decreasing the item size of candies led participants to decrease by half their gram weight intake, resulting in an energy intake decrease of 60 kcal compared to the other group. Appetite ratings and subject and food characteristics had no moderating effect. A cognitive bias could explain why people tend to consider that one unit of food (eg, 10 candies) is the appropriate amount to consume, regardless of the size of the food items in the unit. This study suggests a simple dietary strategy, decreasing food-item size without having to alter the portion size offered, may reduce energy intake at snacking occasions. Copyright © 2011 American Dietetic Association. Published by Elsevier Inc. All rights reserved.

  2. Tailored Cloze: Improved with Classical Item Analysis Techniques.

    Science.gov (United States)

    Brown, James Dean

    1988-01-01

    The reliability and validity of a cloze procedure used as an English-as-a-second-language (ESL) test in China were improved by applying traditional item analysis and selection techniques. The 'best' test items were chosen on the basis of item facility and discrimination indices, and were administered as a 'tailored cloze.' 29 references listed.…

  3. Electronics. Criterion-Referenced Test (CRT) Item Bank.

    Science.gov (United States)

    Davis, Diane, Ed.

    This document contains 519 criterion-referenced multiple choice and true or false test items for a course in electronics. The test item bank is designed to work with both the Vocational Instructional Management System (VIMS) and the Vocational Administrative Management System (VAMS) in Missouri. The items are grouped into 15 units covering the…

  4. Guide to good practices for the development of test items

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    While the methodology used in developing test items can vary significantly, to ensure quality examinations, test items should be developed systematically. Test design and development is discussed in the DOE Guide to Good Practices for Design, Development, and Implementation of Examinations. This guide is intended to be a supplement by providing more detailed guidance on the development of specific test items. This guide addresses the development of written examination test items primarily. However, many of the concepts also apply to oral examinations, both in the classroom and on the job. This guide is intended to be used as guidance for the classroom and laboratory instructor or curriculum developer responsible for the construction of individual test items. This document focuses on written test items, but includes information relative to open-reference (open book) examination test items, as well. These test items have been categorized as short-answer, multiple-choice, or essay. Each test item format is described, examples are provided, and a procedure for development is included. The appendices provide examples for writing test items, a test item development form, and examples of various test item formats.

  5. 41 CFR 101-27.209-1 - GSA stock items.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 2 2010-07-01 2010-07-01 true GSA stock items. 101-27.209-1 Section 101-27.209-1 Public Contracts and Property Management Federal Property Management...-Management of Shelf-Life Materials § 101-27.209-1 GSA stock items. Shelf-life items that meet the criteria...

  6. Effect of Differential Item Functioning on Test Equating

    Science.gov (United States)

    Kabasakal, Kübra Atalay; Kelecioglu, Hülya

    2015-01-01

    This study examines the effect of differential item functioning (DIF) items on test equating through multilevel item response models (MIRMs) and traditional IRMs. The performances of three different equating models were investigated under 24 different simulation conditions, and the variables whose effects were examined included sample size, test…

  7. ACER Chemistry Test Item Collection (ACER CHEMTIC Year 12 Supplement).

    Science.gov (United States)

    Australian Council for Educational Research, Hawthorn.

    This publication contains 317 multiple-choice chemistry test items related to topics covered in the Victorian (Australia) Year 12 chemistry course. It allows teachers access to a range of items suitable for diagnostic and achievement purposes, supplementing the ACER Chemistry Test Item Collection--Year 12 (CHEMTIC). The topics covered are: organic…

  8. Computerized adaptive testing item selection in computerized adaptive learning systems

    NARCIS (Netherlands)

    Eggen, Theodorus Johannes Hendrikus Maria; Eggen, T.J.H.M.; Veldkamp, B.P.

    2012-01-01

    Item selection methods traditionally developed for computerized adaptive testing (CAT) are explored for their usefulness in item-based computerized adaptive learning (CAL) systems. While in CAT Fisher information-based selection is optimal, for recovering learning populations in CAL systems item

  9. 12 CFR 210.8 - Presenting noncash items for acceptance.

    Science.gov (United States)

    2010-01-01

    ... for acceptance. (a) A Reserve Bank or a subsequent collecting bank may, if instructed by the sender, present a noncash item for acceptance in any manner authorized by law if— (1) The item provides that it... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Presenting noncash items for acceptance. 210.8...

  10. Writing, Evaluating and Assessing Data Response Items in Economics.

    Science.gov (United States)

    Trotman-Dickenson, D. I.

    1989-01-01

    Describes some of the problems in writing data response items in economics for use by A Level and General Certificate of Secondary Education (GCSE) students. Examines the experience of two series of workshops on writing items, evaluating them and assessing responses from schools. Offers suggestions for producing packages of data response items as…

  11. A scale purification procedure for evaluation of differential item functioning

    NARCIS (Netherlands)

    Khalid, Muhammad Naveed; Glas, Cornelis A.W.

    2014-01-01

    Item bias or differential item functioning (DIF) has an important impact on the fairness of psychological and educational testing. In this paper, DIF is seen as a lack of fit to an item response (IRT) model. Inferences about the presence and importance of DIF require a process of so-called test

  12. Comparing Two Versions of the MEOCS Using Differential Item Functioning

    National Research Council Canada - National Science Library

    Truhon, Stephen

    2003-01-01

    ...) from item response theory (IRT). DIF was found for the majority of the 40 items examined, although in many cases the DIF indicated improvements in the revised items. Implications for these scales and for the use of IRT with the MEOCS are discussed.

  13. Item Response Theory Models for Performance Decline during Testing

    Science.gov (United States)

    Jin, Kuan-Yu; Wang, Wen-Chung

    2014-01-01

    Sometimes, test-takers may not be able to attempt all items to the best of their ability (with full effort) due to personal factors (e.g., low motivation) or testing conditions (e.g., time limit), resulting in poor performances on certain items, especially those located toward the end of a test. Standard item response theory (IRT) models fail to…

  14. Vegetable parenting practices scale: Item response modeling analyses

    Science.gov (United States)

    Our objective was to evaluate the psychometric properties of a vegetable parenting practices scale using multidimensional polytomous item response modeling which enables assessing item fit to latent variables and the distributional characteristics of the items in comparison to the respondents. We al...

  15. Examination of the PROMIS upper extremity item bank.

    Science.gov (United States)

    Hung, Man; Voss, Maren W; Bounsanga, Jerry; Crum, Anthony B; Tyser, Andrew R

    Clinical measurement. The psychometric properties of the PROMIS v1.2 UE item bank were tested on various samples prior to its release, but have not been fully evaluated among the orthopaedic population. This study assesses the performance of the UE item bank within the UE orthopaedic patient population. The UE item bank was administered to 1197 adult patients presenting to a tertiary orthopaedic clinic specializing in hand and UE conditions and was examined using traditional statistics and Rasch analysis. The UE item bank fits a unidimensional model (outfit MNSQ range from 0.64 to 1.70) and has adequate reliabilities (person = 0.84; item = 0.82) and local independence (item residual correlations range from -0.37 to 0.34). Only one item exhibits gender differential item functioning. Most items target low levels of function. The UE item bank is a useful clinical assessment tool. Additional items covering higher functions are needed to enhance validity. Supplemental testing is recommended for patients at higher levels of function until more high function UE items are developed. 2c. Copyright © 2016 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.

  16. DIF Trees: Using Classification Trees to Detect Differential Item Functioning

    Science.gov (United States)

    Vaughn, Brandon K.; Wang, Qiu

    2010-01-01

    A nonparametric tree classification procedure is used to detect differential item functioning for items that are dichotomously scored. Classification trees are shown to be an alternative procedure to detect differential item functioning other than the use of traditional Mantel-Haenszel and logistic regression analysis. A nonparametric…

  17. A simple and fast item selection procedure for adaptive testing

    NARCIS (Netherlands)

    Veerkamp, W.J.J.; Veerkamp, Wim J.J.; Berger, Martijn; Berger, Martijn P.F.

    1994-01-01

    Items with the highest discrimination parameter values in a logistic item response theory (IRT) model do not necessarily give maximum information. This paper shows which discrimination parameter values (as a function of the guessing parameter and the distance between person ability and item

  18. Optimal item discrimination and maximum information for logistic IRT models

    NARCIS (Netherlands)

    Veerkamp, W.J.J.; Veerkamp, Wim J.J.; Berger, Martijn P.F.; Berger, Martijn

    1999-01-01

    Items with the highest discrimination parameter values in a logistic item response theory model do not necessarily give maximum information. This paper derives discrimination parameter values, as functions of the guessing parameter and distances between person parameters and item difficulty, that

  19. An NCME Instructional Module on Item-Fit Statistics for Item Response Theory Models

    Science.gov (United States)

    Ames, Allison J.; Penfield, Randall D.

    2015-01-01

    Drawing valid inferences from item response theory (IRT) models is contingent upon a good fit of the data to the model. Violations of model-data fit have numerous consequences, limiting the usefulness and applicability of the model. This instructional module provides an overview of methods used for evaluating the fit of IRT models. Upon completing…

  20. Methods for Assessing Item, Step, and Threshold Invariance in Polytomous Items Following the Partial Credit Model

    Science.gov (United States)

    Penfield, Randall D.; Myers, Nicholas D.; Wolfe, Edward W.

    2008-01-01

    Measurement invariance in the partial credit model (PCM) can be conceptualized in several different but compatible ways. In this article the authors distinguish between three forms of measurement invariance in the PCM: step invariance, item invariance, and threshold invariance. Approaches for modeling these three forms of invariance are proposed,…

  1. Detection of Uniform and Nonuniform Differential Item Functioning by Item-Focused Trees

    Science.gov (United States)

    Berger, Moritz; Tutz, Gerhard

    2016-01-01

    Detection of differential item functioning (DIF) by use of the logistic modeling approach has a long tradition. One big advantage of the approach is that it can be used to investigate nonuniform (NUDIF) as well as uniform DIF (UDIF). The classical approach allows one to detect DIF by distinguishing between multiple groups. We propose an…

  2. The Relative Importance of Persons, Items, Subtests, and Languages to TOEFL Test Variance.

    Science.gov (United States)

    Brown, James Dean

    1999-01-01

    Explored the relative contributions to Test of English as a Foreign Language (TOEFL) score dependability of various numbers of persons, items, subtests, languages, and their various interactions. Sampled 15,000 test takers, 1000 each from 15 different language backgrounds. (Author/VWL)

  3. Testing the Item-Order Account of Design Effects Using the Production Effect

    Science.gov (United States)

    Jonker, Tanya R.; Levene, Merrick; MacLeod, Colin M.

    2014-01-01

    A number of memory phenomena evident in recall in within-subject, mixed-lists designs are reduced or eliminated in between-subject, pure-list designs. The item-order account (McDaniel & Bugg, 2008) proposes that differential retention of order information might underlie this pattern. According to this account, order information may be encoded…

  4. Development of Abbreviated Nine-Item Forms of the Raven's Standard Progressive Matrices Test

    Science.gov (United States)

    Bilker, Warren B.; Hansen, John A.; Brensinger, Colleen M.; Richard, Jan; Gur, Raquel E.; Gur, Ruben C.

    2012-01-01

    The Raven's Standard Progressive Matrices (RSPM) is a 60-item test for measuring abstract reasoning, considered a nonverbal estimate of fluid intelligence, and often included in clinical assessment batteries and research on patients with cognitive deficits. The goal was to develop and apply a predictive model approach to reduce the number of items…

  5. The 12-item World Health Organization Disability Assessment Schedule II (WHO-DAS II: a nonparametric item response analysis

    Directory of Open Access Journals (Sweden)

    Fernandez Ana

    2010-05-01

    Full Text Available Abstract Background Previous studies have analyzed the psychometric properties of the World Health Organization Disability Assessment Schedule II (WHO-DAS II using classical omnibus measures of scale quality. These analyses are sample dependent and do not model item responses as a function of the underlying trait level. The main objective of this study was to examine the effectiveness of the WHO-DAS II items and their options in discriminating between changes in the underlying disability level by means of item response analyses. We also explored differential item functioning (DIF in men and women. Methods The participants were 3615 adult general practice patients from 17 regions of Spain, with a first diagnosed major depressive episode. The 12-item WHO-DAS II was administered by the general practitioners during the consultation. We used a non-parametric item response method (Kernel-Smoothing implemented with the TestGraf software to examine the effectiveness of each item (item characteristic curves and their options (option characteristic curves in discriminating between changes in the underliying disability level. We examined composite DIF to know whether women had a higher probability than men of endorsing each item. Results Item response analyses indicated that the twelve items forming the WHO-DAS II perform very well. All items were determined to provide good discrimination across varying standardized levels of the trait. The items also had option characteristic curves that showed good discrimination, given that each increasing option became more likely than the previous as a function of increasing trait level. No gender-related DIF was found on any of the items. Conclusions All WHO-DAS II items were very good at assessing overall disability. Our results supported the appropriateness of the weights assigned to response option categories and showed an absence of gender differences in item functioning.

  6. Are great apes able to reason from multi-item samples to populations of food items?

    Science.gov (United States)

    Eckert, Johanna; Rakoczy, Hannes; Call, Josep

    2017-10-01

    Inductive learning from limited observations is a cognitive capacity of fundamental importance. In humans, it is underwritten by our intuitive statistics, the ability to draw systematic inferences from populations to randomly drawn samples and vice versa. According to recent research in cognitive development, human intuitive statistics develops early in infancy. Recent work in comparative psychology has produced first evidence for analogous cognitive capacities in great apes who flexibly drew inferences from populations to samples. In the present study, we investigated whether great apes (Pongo abelii, Pan troglodytes, Pan paniscus, Gorilla gorilla) also draw inductive inferences in the opposite direction, from samples to populations. In two experiments, apes saw an experimenter randomly drawing one multi-item sample from each of two populations of food items. The populations differed in their proportion of preferred to neutral items (24:6 vs. 6:24) but apes saw only the distribution of food items in the samples that reflected the distribution of the respective populations (e.g., 4:1 vs. 1:4). Based on this observation they were then allowed to choose between the two populations. Results show that apes seemed to make inferences from samples to populations and thus chose the population from which the more favorable (4:1) sample was drawn in Experiment 1. In this experiment, the more attractive sample not only contained proportionally but also absolutely more preferred food items than the less attractive sample. Experiment 2, however, revealed that when absolute and relative frequencies were disentangled, apes performed at chance level. Whether these limitations in apes' performance reflect true limits of cognitive competence or merely performance limitations due to accessory task demands is still an open question. © 2017 Wiley Periodicals, Inc.

  7. Location Indices for Ordinal Polytomous Items Based on Item Response Theory. Research Report. ETS RR-15-20

    Science.gov (United States)

    Ali, Usama S.; Chang, Hua-Hua; Anderson, Carolyn J.

    2015-01-01

    Polytomous items are typically described by multiple category-related parameters; situations, however, arise in which a single index is needed to describe an item's location along a latent trait continuum. Situations in which a single index would be needed include item selection in computerized adaptive testing or test assembly. Therefore single…

  8. Science Library of Test Items. Volume Twenty-Two. A Collection of Multiple Choice Test Items Relating Mainly to Skills.

    Science.gov (United States)

    New South Wales Dept. of Education, Sydney (Australia).

    As one in a series of test item collections developed by the Assessment and Evaluation Unit of the Directorate of Studies, items are made available to teachers for the construction of unit tests or term examinations or as a basis for class discussion. Each collection was reviewed for content validity and reliability. The test items meet syllabus…

  9. Science Library of Test Items. Volume Eighteen. A Collection of Multiple Choice Test Items Relating Mainly to Chemistry.

    Science.gov (United States)

    New South Wales Dept. of Education, Sydney (Australia).

    As one in a series of test item collections developed by the Assessment and Evaluation Unit of the Directorate of Studies, items are made available to teachers for the construction of unit tests or term examinations or as a basis for class discussion. Each collection was reviewed for content validity and reliability. The test items meet syllabus…

  10. Science Library of Test Items. Volume Twenty. A Collection of Multiple Choice Test Items Relating Mainly to Physics, 1.

    Science.gov (United States)

    New South Wales Dept. of Education, Sydney (Australia).

    As one in a series of test item collections developed by the Assessment and Evaluation Unit of the Directorate of Studies, items are made available to teachers for the construction of unit tests or term examinations or as a basis for class discussion. Each collection was reviewed for content validity and reliability. The test items meet syllabus…

  11. Science Library of Test Items. Volume Seventeen. A Collection of Multiple Choice Test Items Relating Mainly to Biology.

    Science.gov (United States)

    New South Wales Dept. of Education, Sydney (Australia).

    As one in a series of test item collections developed by the Assessment and Evaluation Unit of the Directorate of Studies, items are made available to teachers for the construction of unit tests or term examinations or as a basis for class discussion. Each collection was reviewed for content validity and reliability. The test items meet syllabus…

  12. Science Library of Test Items. Volume Nineteen. A Collection of Multiple Choice Test Items Relating Mainly to Geology.

    Science.gov (United States)

    New South Wales Dept. of Education, Sydney (Australia).

    As one in a series of test item collections developed by the Assessment and Evaluation Unit of the Directorate of Studies, items are made available to teachers for the construction of unit tests or term examinations or as a basis for class discussion. Each collection was reviewed for content validity and reliability. The test items meet syllabus…

  13. Criteria for eliminating items of a Test of Figural Analogies

    Directory of Open Access Journals (Sweden)

    Diego Blum

    2013-12-01

    Full Text Available This paper describes the steps taken to eliminate two of the items in a Test of Figural Analogies (TFA. The main guidelines of psychometric analysis concerning Classical Test Theory (CTT and Item Response Theory (IRT are explained. The item elimination process was based on both the study of the CTT difficulty and discrimination index, and the unidimensionality analysis. The a, b, and c parameters of the Three Parameter Logistic Model of IRT were also considered for this purpose, as well as the assessment of each item fitting this model. The unfavourable characteristics of a group of TFA items are detailed, and decisions leading to their possible elimination are discussed.

  14. Item and response-category functioning of the Persian version of the KIDSCREEN-27: Rasch partial credit model

    Directory of Open Access Journals (Sweden)

    Jafari Peyman

    2012-10-01

    Full Text Available Abstract Background The purpose of the study was to determine whether the Persian version of the KIDSCREEN-27 has the optimal number of response category to measure health-related quality of life (HRQoL in children and adolescents. Moreover, we aimed to determine if all the items contributed adequately to their own domain. Findings The Persian version of the KIDSCREEN-27 was completed by 1083 school children and 1070 of their parents. The Rasch partial credit model (PCM was used to investigate item statistics and ordering of response categories. The PCM showed that no item was misfitting. The PCM also revealed that, successive response categories for all items were located in the expected order except for category 1 in self- and proxy-reports. Conclusions Although Rasch analysis confirms that all the items belong to their own underlying construct, response categories should be reorganized and evaluated in further studies, especially in children with chronic conditions.

  15. Predictive validity of the Work Ability Index and its individual items in the general population.

    Science.gov (United States)

    Lundin, Andreas; Leijon, Ola; Vaez, Marjan; Hallgren, Mats; Torgén, Margareta

    2017-06-01

    This study assesses the predictive ability of the full Work Ability Index (WAI) as well as its individual items in the general population. The Work, Health and Retirement Study (WHRS) is a stratified random national sample of 25-75-year-olds living in Sweden in 2000 that received a postal questionnaire ( n = 6637, response rate = 53%). Current and subsequent sickness absence was obtained from registers. The ability of the WAI to predict long-term sickness absence (LTSA; ⩾ 90 consecutive days) during a period of four years was analysed by logistic regression, from which the Area Under the Receiver Operating Characteristic curve (AUC) was computed. There were 313 incident LTSA cases among 1786 employed individuals. The full WAI had acceptable ability to predict LTSA during the 4-year follow-up (AUC = 0.79; 95% CI 0.76 to 0.82). Individual items were less stable in their predictive ability. However, three of the individual items: current work ability compared with lifetime best, estimated work impairment due to diseases, and number of diagnosed current diseases, exceeded AUC > 0.70. Excluding the WAI item on number of days on sickness absence did not result in an inferior predictive ability of the WAI. The full WAI has acceptable predictive validity, and is superior to its individual items. For public health surveys, three items may be suitable proxies of the full WAI; current work ability compared with lifetime best, estimated work impairment due to diseases, and number of current diseases diagnosed by a physician.

  16. Sources of interference in item and associative recognition memory.

    Science.gov (United States)

    Osth, Adam F; Dennis, Simon

    2015-04-01

    A powerful theoretical framework for exploring recognition memory is the global matching framework, in which a cue's memory strength reflects the similarity of the retrieval cues being matched against the contents of memory simultaneously. Contributions at retrieval can be categorized as matches and mismatches to the item and context cues, including the self match (match on item and context), item noise (match on context, mismatch on item), context noise (match on item, mismatch on context), and background noise (mismatch on item and context). We present a model that directly parameterizes the matches and mismatches to the item and context cues, which enables estimation of the magnitude of each interference contribution (item noise, context noise, and background noise). The model was fit within a hierarchical Bayesian framework to 10 recognition memory datasets that use manipulations of strength, list length, list strength, word frequency, study-test delay, and stimulus class in item and associative recognition. Estimates of the model parameters revealed at most a small contribution of item noise that varies by stimulus class, with virtually no item noise for single words and scenes. Despite the unpopularity of background noise in recognition memory models, background noise estimates dominated at retrieval across nearly all stimulus classes with the exception of high frequency words, which exhibited equivalent levels of context noise and background noise. These parameter estimates suggest that the majority of interference in recognition memory stems from experiences acquired before the learning episode. (c) 2015 APA, all rights reserved).

  17. Feed mechanism and method for feeding minute items

    Science.gov (United States)

    Stringer, Timothy Kent [Bucyrus, KS; Yerganian, Simon Scott [Lee's Summit, MO

    2009-10-20

    A feeding mechanism and method for feeding minute items, such as capacitors, resistors, or solder preforms. The mechanism is adapted to receive a plurality of the randomly-positioned and randomly-oriented extremely small or minute items, and to isolate, orient, and position one or more of the items in a specific repeatable pickup location wherefrom they may be removed for use by, for example, a computer-controlled automated assembly machine. The mechanism comprises a sliding shelf adapted to receive and support the items; a wiper arm adapted to achieve a single even layer of the items; and a pushing arm adapted to push the items into the pickup location. The mechanism can be adapted for providing the items with a more exact orientation, and can also be adapted for use in a liquid environment.

  18. Negative affect impairs associative memory but not item memory.

    Science.gov (United States)

    Bisby, James A; Burgess, Neil

    2013-12-17

    The formation of associations between items and their context has been proposed to rely on mechanisms distinct from those supporting memory for a single item. Although emotional experiences can profoundly affect memory, our understanding of how it interacts with different aspects of memory remains unclear. We performed three experiments to examine the effects of emotion on memory for items and their associations. By presenting neutral and negative items with background contexts, Experiment 1 demonstrated that item memory was facilitated by emotional affect, whereas memory for an associated context was reduced. In Experiment 2, arousal was manipulated independently of the memoranda, by a threat of shock, whereby encoding trials occurred under conditions of threat or safety. Memory for context was equally impaired by the presence of negative affect, whether induced by threat of shock or a negative item, relative to retrieval of the context of a neutral item in safety. In Experiment 3, participants were presented with neutral and negative items as paired associates, including all combinations of neutral and negative items. The results showed both above effects: compared to a neutral item, memory for the associate of a negative item (a second item here, context in Experiments 1 and 2) is impaired, whereas retrieval of the item itself is enhanced. Our findings suggest that negative affect impairs associative memory while recognition of a negative item is enhanced. They support dual-processing models in which negative affect or stress impairs hippocampal-dependent associative memory while the storage of negative sensory/perceptual representations is spared or even strengthened.

  19. A note on the eigensystem of the covariance matrix of dichotomous Guttman items

    Directory of Open Access Journals (Sweden)

    Clintin P Davis-Stober

    2015-12-01

    Full Text Available We consider the sample covariance matrix for dichotomous Guttman items under a set of uniformity conditions, and obtain closed-form expressions for the eigenvalues and eigenvectors of the matrix. In particular, we describe the eigenvalues and eigenvectors of the matrix in terms of trigonometric functions of the number of items. Our results parallel those of Zwick (1987 for the correlation matrix under the same uniformity conditions. We provide an explanation for certain properties of principal components under Guttman scalability which have been first reported by Guttman (1950.

  20. A Note on the Eigensystem of the Covariance Matrix of Dichotomous Guttman Items.

    Science.gov (United States)

    Davis-Stober, Clintin P; Doignon, Jean-Paul; Suck, Reinhard

    2015-01-01

    We consider the covariance matrix for dichotomous Guttman items under a set of uniformity conditions, and obtain closed-form expressions for the eigenvalues and eigenvectors of the matrix. In particular, we describe the eigenvalues and eigenvectors of the matrix in terms of trigonometric functions of the number of items. Our results parallel those of Zwick (1987) for the correlation matrix under the same uniformity conditions. We provide an explanation for certain properties of principal components under Guttman scalability which have been first reported by Guttman (1950).

  1. NFC based Equipment Qualification Management (NEQM) system preventing counterfeit and fraudulent item

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C.K., E-mail: ckchang@kings.ac.kr [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of); Lee, K.J., E-mail: klee@khu.ac.kr [Kyung Hee Univ., Seoul (Korea, Republic of)

    2014-07-01

    Qualification of equipment essential to safety in nuclear power plants (NPPs) ensures its capability to perform designated safety functions on demand under postulated service conditions. However, a number of incidents identified by the NRC since 1980s catalysed the US nuclear industry to adopt standard precautions to guard against counterfeit items. The purpose of this paper is to suggest the NFC (Near Field Communication) based equipment qualification management system preventing counterfeit and fraudulent items. The NEQM (NFC based Equipment Qualification Management) system work with the support of legacy systems such as PMS (Procurement Management System) and FMS (Facility management System). (author)

  2. NFC based Equipment Qualification Management (NEQM) system preventing counterfeit and fraudulent item

    International Nuclear Information System (INIS)

    Chang, C.K.; Lee, K.J.

    2014-01-01

    Qualification of equipment essential to safety in nuclear power plants (NPPs) ensures its capability to perform designated safety functions on demand under postulated service conditions. However, a number of incidents identified by the NRC since 1980s catalysed the US nuclear industry to adopt standard precautions to guard against counterfeit items. The purpose of this paper is to suggest the NFC (Near Field Communication) based equipment qualification management system preventing counterfeit and fraudulent items. The NEQM (NFC based Equipment Qualification Management) system work with the support of legacy systems such as PMS (Procurement Management System) and FMS (Facility management System). (author)

  3. Development of an item bank for food parenting practices based on published instruments and reports from Canadian and US parents.

    Science.gov (United States)

    O'Connor, Teresia M; Pham, Truc; Watts, Allison W; Tu, Andrew W; Hughes, Sheryl O; Beauchamp, Mark R; Baranowski, Tom; Mâsse, Louise C

    2016-08-01

    Research to understand how parents influence their children's dietary intake and eating behaviors has expanded in the past decades and a growing number of instruments are available to assess food parenting practices. Unfortunately, there is no consensus on how constructs should be defined or operationalized, making comparison of results across studies difficult. The aim of this study was to develop a food parenting practice item bank with items from published scales and supplement with parenting practices that parents report using. Items from published scales were identified from two published systematic reviews along with an additional systematic review conducted for this study. Parents (n = 135) with children 5-12 years old from the US and Canada, stratified to represent the demographic distribution of each country, were recruited to participate in an online semi-qualitative survey on food parenting. Published items and parent responses were coded using the same framework to reduce the number of items into representative concepts using a binning and winnowing process. The literature contributed 1392 items and parents contributed 1985 items, which were reduced to 262 different food parenting concepts (26% exclusive from literature, 12% exclusive from parents, and 62% represented in both). Food parenting practices related to 'Structure of Food Environment' and 'Behavioral and Educational' were emphasized more by parent responses, while practices related to 'Consistency of Feeding Environment' and 'Emotional Regulation' were more represented among published items. The resulting food parenting item bank should next be calibrated with item response modeling for scientists to use in the future. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Item Response Theory with Covariates (IRT-C): Assessing Item Recovery and Differential Item Functioning for the Three-Parameter Logistic Model

    Science.gov (United States)

    Tay, Louis; Huang, Qiming; Vermunt, Jeroen K.

    2016-01-01

    In large-scale testing, the use of multigroup approaches is limited for assessing differential item functioning (DIF) across multiple variables as DIF is examined for each variable separately. In contrast, the item response theory with covariate (IRT-C) procedure can be used to examine DIF across multiple variables (covariates) simultaneously. To…

  5. Which Statistic Should Be Used to Detect Item Preknowledge When the Set of Compromised Items Is Known?

    Science.gov (United States)

    Sinharay, Sandip

    2017-09-01

    Benefiting from item preknowledge is a major type of fraudulent behavior during educational assessments. Belov suggested the posterior shift statistic for detection of item preknowledge and showed its performance to be better on average than that of seven other statistics for detection of item preknowledge for a known set of compromised items. Sinharay suggested a statistic based on the likelihood ratio test for detection of item preknowledge; the advantage of the statistic is that its null distribution is known. Results from simulated and real data and adaptive and nonadaptive tests are used to demonstrate that the Type I error rate and power of the statistic based on the likelihood ratio test are very similar to those of the posterior shift statistic. Thus, the statistic based on the likelihood ratio test appears promising in detecting item preknowledge when the set of compromised items is known.

  6. Does remembering emotional items impair recall of same-emotion items?

    Science.gov (United States)

    Sison, Jo Ann G; Mather, Mara

    2007-04-01

    In the part-set cuing effect, cuing a subset of previously studied items impairs recall of the remaining noncued items. This experiment reveals that cuing participants with previously-studied emotional pictures (e.g., fear-evoking pictures of people) can impair recall of pictures involving the same emotion but different content (e.g., fear-evoking pictures of animals). This indicates that new events can be organized in memory using emotion as a grouping function to create associations. However, whether new information is organized in memory along emotional or nonemotional lines appears to be a flexible process that depends on people's current focus. Mentioning in the instructions that the pictures were either amusement- or fear-related led to memory impairment for pictures with the same emotion as cued pictures, whereas mentioning that the pictures depicted either animals or people led to memory impairment for pictures with the same type of actor.

  7. Statistical power as a function of Cronbach alpha of instrument questionnaire items.

    Science.gov (United States)

    Heo, Moonseong; Kim, Namhee; Faith, Myles S

    2015-10-14

    In countless number of clinical trials, measurements of outcomes rely on instrument questionnaire items which however often suffer measurement error problems which in turn affect statistical power of study designs. The Cronbach alpha or coefficient alpha, here denoted by C(α), can be used as a measure of internal consistency of parallel instrument items that are developed to measure a target unidimensional outcome construct. Scale score for the target construct is often represented by the sum of the item scores. However, power functions based on C(α) have been lacking for various study designs. We formulate a statistical model for parallel items to derive power functions as a function of C(α) under several study designs. To this end, we assume fixed true score variance assumption as opposed to usual fixed total variance assumption. That assumption is critical and practically relevant to show that smaller measurement errors are inversely associated with higher inter-item correlations, and thus that greater C(α) is associated with greater statistical power. We compare the derived theoretical statistical power with empirical power obtained through Monte Carlo simulations for the following comparisons: one-sample comparison of pre- and post-treatment mean differences, two-sample comparison of pre-post mean differences between groups, and two-sample comparison of mean differences between groups. It is shown that C(α) is the same as a test-retest correlation of the scale scores of parallel items, which enables testing significance of C(α). Closed-form power functions and samples size determination formulas are derived in terms of C(α), for all of the aforementioned comparisons. Power functions are shown to be an increasing function of C(α), regardless of comparison of interest. The derived power functions are well validated by simulation studies that show that the magnitudes of theoretical power are virtually identical to those of the empirical power. Regardless

  8. Editorial Changes and Item Performance: Implications for Calibration and Pretesting

    Directory of Open Access Journals (Sweden)

    Heather Stoffel

    2014-11-01

    Full Text Available Previous research on the impact of text and formatting changes on test-item performance has produced mixed results. This matter is important because it is generally acknowledged that any change to an item requires that it be recalibrated. The present study investigated the effects of seven classes of stylistic changes on item difficulty, discrimination, and response time for a subset of 65 items that make up a standardized test for physician licensure completed by 31,918 examinees in 2012. One of two versions of each item (original or revised was randomly assigned to examinees such that each examinee saw only two experimental items, with each item being administered to approximately 480 examinees. The stylistic changes had little or no effect on item difficulty or discrimination; however, one class of edits -' changing an item from an open lead-in (incomplete statement to a closed lead-in (direct question -' did result in slightly longer response times. Data for nonnative speakers of English were analyzed separately with nearly identical results. These findings have implications for the conventional practice of repretesting (or recalibrating items that have been subjected to minor editorial changes.

  9. A note on monotonicity of item response functions for ordered polytomous item response theory models.

    Science.gov (United States)

    Kang, Hyeon-Ah; Su, Ya-Hui; Chang, Hua-Hua

    2018-03-08

    A monotone relationship between a true score (τ) and a latent trait level (θ) has been a key assumption for many psychometric applications. The monotonicity property in dichotomous response models is evident as a result of a transformation via a test characteristic curve. Monotonicity in polytomous models, in contrast, is not immediately obvious because item response functions are determined by a set of response category curves, which are conceivably non-monotonic in θ. The purpose of the present note is to demonstrate strict monotonicity in ordered polytomous item response models. Five models that are widely used in operational assessments are considered for proof: the generalized partial credit model (Muraki, 1992, Applied Psychological Measurement, 16, 159), the nominal model (Bock, 1972, Psychometrika, 37, 29), the partial credit model (Masters, 1982, Psychometrika, 47, 147), the rating scale model (Andrich, 1978, Psychometrika, 43, 561), and the graded response model (Samejima, 1972, A general model for free-response data (Psychometric Monograph no. 18). Psychometric Society, Richmond). The study asserts that the item response functions in these models strictly increase in θ and thus there exists strict monotonicity between τ and θ under certain specified conditions. This conclusion validates the practice of customarily using τ in place of θ in applied settings and provides theoretical grounds for one-to-one transformations between the two scales. © 2018 The British Psychological Society.

  10. A Study on the Systematization of Classification Process for NSG Trigger List Items

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Seunghyo; Tae, Jaewoong; Shin, Donghoon [Korea Institute of Nuclear Nonproliferation and Control/Nuclear Export Control Div., Daejeon (Korea, Republic of)

    2013-05-15

    In 1978, Nuclear Suppliers Group (NSG) was established to prevent nuclear items from being used for nuclear weapons. NSG drew up the NSG Guidelines (INFCIRC/254) that regulates export control items(so-called NSG trigger list items) and procedures. NSG recommends its member countries to reflect these guidelines on their export control systems and fulfill their obligations. Korea has carried out export controls on nuclear items by reflecting NSG Guidelines on Notice on Trade of Strategic Item of Foreign Trade Act since joining NSG in 1995. Nuclear export control starts with Classification that determines whether export items can be used for strategic items (goods and technologies that can be exclusively used for the manufacture, development and use of WMD). The standard of Classification is based on the NSG Guidelines. However, due to the qualitative characteristics of the Guidelines, there take place lots of difficulties in the Classification. Thus this study aims to suggest the systematic Classification process. Recently, the number of Classification requests is rapidly increasing due to the UAE commercial nuclear power plants and the Jordan reactors export. It is required to provide a more systematic Classification standard and process in order to provide an efficient and consistent Classification. Thus, this study analyzed limitations of EDP which causes difficulties in the process of classification due to its qualitative characteristics. Besides, it established systematic Classification process by quantitatively analyzing EDP. Consequently, it is expected that the results of this study will be used for as actual Classification. It still remains to establish a criterion of detailed information, which is one of the most important in the Classification for technology. Therefore, a further study will be conducted to establish a criterion of detailed information by analyzing Classification cases through the text mining techniques.

  11. Item response theory analysis applied to the Spanish version of the Personal Outcomes Scale.

    Science.gov (United States)

    Guàrdia-Olmos, J; Carbó-Carreté, M; Peró-Cebollero, M; Giné, C

    2017-11-01

    The study of measurements of quality of life (QoL) is one of the great challenges of modern psychology and psychometric approaches. This issue has greater importance when examining QoL in populations that were historically treated on the basis of their deficiency, and recently, the focus has shifted to what each person values and desires in their life, as in cases of people with intellectual disability (ID). Many studies of QoL scales applied in this area have attempted to improve the validity and reliability of their components by incorporating various sources of information to achieve consistency in the data obtained. The adaptation of the Personal Outcomes Scale (POS) in Spanish has shown excellent psychometric attributes, and its administration has three sources of information: self-assessment, practitioner and family. The study of possible congruence or incongruence of observed distributions of each item between sources is therefore essential to ensure a correct interpretation of the measure. The aim of this paper was to analyse the observed distribution of items and dimensions from the three Spanish POS information sources cited earlier, using the item response theory. We studied a sample of 529 people with ID and their respective practitioners and family member, and in each case, we analysed items and factors using Samejima's model of polytomic ordinal scales. The results indicated an important number of items with differential effects regarding sources, and in some cases, they indicated significant differences in the distribution of items, factors and sources of information. As a result of this analysis, we must affirm that the administration of the POS, considering three sources of information, was adequate overall, but a correct interpretation of the results requires that it obtain much more information to consider, as well as some specific items in specific dimensions. The overall ratings, if these comments are considered, could result in bias. © 2017

  12. A Study on the Systematization of Classification Process for NSG Trigger List Items

    International Nuclear Information System (INIS)

    Yang, Seunghyo; Tae, Jaewoong; Shin, Donghoon

    2013-01-01

    In 1978, Nuclear Suppliers Group (NSG) was established to prevent nuclear items from being used for nuclear weapons. NSG drew up the NSG Guidelines (INFCIRC/254) that regulates export control items(so-called NSG trigger list items) and procedures. NSG recommends its member countries to reflect these guidelines on their export control systems and fulfill their obligations. Korea has carried out export controls on nuclear items by reflecting NSG Guidelines on Notice on Trade of Strategic Item of Foreign Trade Act since joining NSG in 1995. Nuclear export control starts with Classification that determines whether export items can be used for strategic items (goods and technologies that can be exclusively used for the manufacture, development and use of WMD). The standard of Classification is based on the NSG Guidelines. However, due to the qualitative characteristics of the Guidelines, there take place lots of difficulties in the Classification. Thus this study aims to suggest the systematic Classification process. Recently, the number of Classification requests is rapidly increasing due to the UAE commercial nuclear power plants and the Jordan reactors export. It is required to provide a more systematic Classification standard and process in order to provide an efficient and consistent Classification. Thus, this study analyzed limitations of EDP which causes difficulties in the process of classification due to its qualitative characteristics. Besides, it established systematic Classification process by quantitatively analyzing EDP. Consequently, it is expected that the results of this study will be used for as actual Classification. It still remains to establish a criterion of detailed information, which is one of the most important in the Classification for technology. Therefore, a further study will be conducted to establish a criterion of detailed information by analyzing Classification cases through the text mining techniques

  13. Number words and number symbols a cultural history of numbers

    CERN Document Server

    Menninger, Karl

    1992-01-01

    Classic study discusses number sequence and language and explores written numerals and computations in many cultures. "The historian of mathematics will find much to interest him here both in the contents and viewpoint, while the casual reader is likely to be intrigued by the author's superior narrative ability.

  14. Binary classification of items of interest in a repeatable process

    Science.gov (United States)

    Abell, Jeffrey A.; Spicer, John Patrick; Wincek, Michael Anthony; Wang, Hui; Chakraborty, Debejyo

    2014-06-24

    A system includes host and learning machines in electrical communication with sensors positioned with respect to an item of interest, e.g., a weld, and memory. The host executes instructions from memory to predict a binary quality status of the item. The learning machine receives signals from the sensor(s), identifies candidate features, and extracts features from the candidates that are more predictive of the binary quality status relative to other candidate features. The learning machine maps the extracted features to a dimensional space that includes most of the items from a passing binary class and excludes all or most of the items from a failing binary class. The host also compares the received signals for a subsequent item of interest to the dimensional space to thereby predict, in real time, the binary quality status of the subsequent item of interest.

  15. The basics of item response theory using R

    CERN Document Server

    Baker, Frank B

    2017-01-01

    This graduate-level textbook is a tutorial for item response theory that covers both the basics of item response theory and the use of R for preparing graphical presentation in writings about the theory. Item response theory has become one of the most powerful tools used in test construction, yet one of the barriers to learning and applying it is the considerable amount of sophisticated computational effort required to illustrate even the simplest concepts. This text provides the reader access to the basic concepts of item response theory freed of the tedious underlying calculations. It is intended for those who possess limited knowledge of educational measurement and psychometrics. Rather than presenting the full scope of item response theory, this textbook is concise and practical and presents basic concepts without becoming enmeshed in underlying mathematical and computational complexities. Clearly written text and succinct R code allow anyone familiar with statistical concepts to explore and apply item re...

  16. Attention restores discrete items to visual short-term memory.

    Science.gov (United States)

    Murray, Alexandra M; Nobre, Anna C; Clark, Ian A; Cravo, André M; Stokes, Mark G

    2013-04-01

    When a memory is forgotten, is it lost forever? Our study shows that selective attention can restore forgotten items to visual short-term memory (VSTM). In our two experiments, all stimuli presented in a memory array were designed to be equally task relevant during encoding. During the retention interval, however, participants were sometimes given a cue predicting which of the memory items would be probed at the end of the delay. This shift in task relevance improved recall for that item. We found that this type of cuing improved recall for items that otherwise would have been irretrievable, providing critical evidence that attention can restore forgotten information to VSTM. Psychophysical modeling of memory performance has confirmed that restoration of information in VSTM increases the probability that the cued item is available for recall but does not improve the representational quality of the memory. We further suggest that attention can restore discrete items to VSTM.

  17. Number skills are maintained in healthy ageing.

    Science.gov (United States)

    Cappelletti, Marinella; Didino, Daniele; Stoianov, Ivilin; Zorzi, Marco

    2014-03-01

    Numerical skills have been extensively studied in terms of their development and pathological decline, but whether they change in healthy ageing is not well known. Longer exposure to numbers and quantity-related problems may progressively refine numerical skills, similar to what happens to other cognitive abilities like verbal memory. Alternatively, number skills may be sensitive to ageing, reflecting either a decline of number processing itself or of more auxiliary cognitive abilities that are involved in number tasks. To distinguish between these possibilities we tested 30 older and 30 younger participants on an established numerosity discrimination task requiring to judge which of two sets of items is more numerous, and on arithmetical tasks. Older participants were remarkably accurate in performing arithmetical tasks although their numerosity discrimination (also known as 'number acuity') was impaired. Further analyses indicate that this impairment was limited to numerosity trials requiring inhibiting information incongruent to numerosity (e.g., fewer but larger items), and that this also correlated with poor inhibitory processes measured by standard tests. Therefore, rather than a numerical impairment, poor numerosity discrimination is likely to reflect elderly's impoverished inhibitory processes. This conclusion is supported by simulations with a recent neuro-computational model of numerosity perception, where only the specific degradation of inhibitory processes produced a pattern that closely resembled older participants' performance. Numeracy seems therefore resilient to ageing but it is influenced by the decline of inhibitory processes supporting number performance, consistent with the 'Inhibitory Deficit' Theory. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Hazardous metals in yellow items used in RCAs

    International Nuclear Information System (INIS)

    Brown, K.F.; Rankin, W.N.

    1992-01-01

    Yellow items used in Radiologically Controlled Areas (RCAs) that could contain hazardous metals were identified. X-ray fluorescence analyses indicated that thirty of the fifty-two items do contain hazardous metals. It is important to minimize the hazardous metals put into the wastes. The authors recommend that the specifications for all yellow items stocked in Stores be changed to specify that they contain no hazardous metals

  19. Safety Evaluation for Packaging (onsite) T Plant Canyon Items

    International Nuclear Information System (INIS)

    OBRIEN, J.H.

    2000-01-01

    This safety evaluation for packaging (SEP) evaluates and documents the ability to safely ship mostly unique inventories of miscellaneous T Plant canyon waste items (T-P Items) encountered during the canyon deck clean off campaign. In addition, this SEP addresses contaminated items and material that may be shipped in a strong tight package (STP). The shipments meet the criteria for onsite shipments as specified by Fluor Hanford in HNF-PRO-154, Responsibilities and Procedures for all Hazardous Material Shipments

  20. Safety Evaluation for Packaging (onsite) T Plant Canyon Items

    Energy Technology Data Exchange (ETDEWEB)

    OBRIEN, J.H.

    2000-07-14

    This safety evaluation for packaging (SEP) evaluates and documents the ability to safely ship mostly unique inventories of miscellaneous T Plant canyon waste items (T-P Items) encountered during the canyon deck clean off campaign. In addition, this SEP addresses contaminated items and material that may be shipped in a strong tight package (STP). The shipments meet the criteria for onsite shipments as specified by Fluor Hanford in HNF-PRO-154, Responsibilities and Procedures for all Hazardous Material Shipments.

  1. Three controversies over item disclosure in medical licensure examinations

    Directory of Open Access Journals (Sweden)

    Yoon Soo Park

    2015-09-01

    Full Text Available In response to views on public's right to know, there is growing attention to item disclosure – release of items, answer keys, and performance data to the public – in medical licensure examinations and their potential impact on the test's ability to measure competence and select qualified candidates. Recent debates on this issue have sparked legislative action internationally, including South Korea, with prior discussions among North American countries dating over three decades. The purpose of this study is to identify and analyze three issues associated with item disclosure in medical licensure examinations – 1 fairness and validity, 2 impact on passing levels, and 3 utility of item disclosure – by synthesizing existing literature in relation to standards in testing. Historically, the controversy over item disclosure has centered on fairness and validity. Proponents of item disclosure stress test takers’ right to know, while opponents argue from a validity perspective. Item disclosure may bias item characteristics, such as difficulty and discrimination, and has consequences on setting passing levels. To date, there has been limited research on the utility of item disclosure for large scale testing. These issues requires ongoing and careful consideration.

  2. Diamond Fuzzy Number

    Directory of Open Access Journals (Sweden)

    T. Pathinathan

    2015-01-01

    Full Text Available In this paper we define diamond fuzzy number with the help of triangular fuzzy number. We include basic arithmetic operations like addition, subtraction of diamond fuzzy numbers with examples. We define diamond fuzzy matrix with some matrix properties. We have defined Nested diamond fuzzy number and Linked diamond fuzzy number. We have further classified Right Linked Diamond Fuzzy number and Left Linked Diamond Fuzzy number. Finally we have verified the arithmetic operations for the above mentioned types of Diamond Fuzzy Numbers.

  3. Those fascinating numbers

    CERN Document Server

    Koninck, Jean-Marie De

    2009-01-01

    Who would have thought that listing the positive integers along with their most remarkable properties could end up being such an engaging and stimulating adventure? The author uses this approach to explore elementary and advanced topics in classical number theory. A large variety of numbers are contemplated: Fermat numbers, Mersenne primes, powerful numbers, sublime numbers, Wieferich primes, insolite numbers, Sastry numbers, voracious numbers, to name only a few. The author also presents short proofs of miscellaneous results and constantly challenges the reader with a variety of old and new n

  4. NFC based Inspection and Qualification Management (NIQM) System Preventing Counterfeit and Fraudulent Item

    International Nuclear Information System (INIS)

    Chang, Choong Koo; Kim, Young Joo

    2013-01-01

    Design, manufacturing, fabrication, transportation and installation of the devices and equipment for nuclear power plants shall be conducted under the thorough quality assurance program for the nuclear safety. However, from late in the 1980s, NRC began to issue a number of communications alerting licenses to issues involving counterfeit and fraudulent items. A number of incidents identified by the NRC in the 1980s and 1990s catalyzed the US nuclear industry to adopt standard precautions to guard against counterfeit items. The purpose of this paper is to develop the NFC (Near Field Communication) based Inspection and Qualification Management(NIQM) system preventing counterfeit and fraudulent items. NFC is one of the latest wireless communication technologies. As a short-range wireless connectivity technology, NFC offers safe-yet simple and intuitive-communication between electronic devices. As described above, NFC technology can be applied to the inspection and qualification management system very effectively to prevent counterfeit and fraudulent items. In addition, NIQM system can use existing data and information through the interface with legacy system

  5. NFC based Inspection and Qualification Management (NIQM) System Preventing Counterfeit and Fraudulent Item

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Choong Koo; Kim, Young Joo [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

    2013-10-15

    Design, manufacturing, fabrication, transportation and installation of the devices and equipment for nuclear power plants shall be conducted under the thorough quality assurance program for the nuclear safety. However, from late in the 1980s, NRC began to issue a number of communications alerting licenses to issues involving counterfeit and fraudulent items. A number of incidents identified by the NRC in the 1980s and 1990s catalyzed the US nuclear industry to adopt standard precautions to guard against counterfeit items. The purpose of this paper is to develop the NFC (Near Field Communication) based Inspection and Qualification Management(NIQM) system preventing counterfeit and fraudulent items. NFC is one of the latest wireless communication technologies. As a short-range wireless connectivity technology, NFC offers safe-yet simple and intuitive-communication between electronic devices. As described above, NFC technology can be applied to the inspection and qualification management system very effectively to prevent counterfeit and fraudulent items. In addition, NIQM system can use existing data and information through the interface with legacy system.

  6. A comparison of discriminant logistic regression and Item Response Theory Likelihood-Ratio Tests for Differential Item Functioning (IRTLRDIF) in polytomous short tests.

    Science.gov (United States)

    Hidalgo, María D; López-Martínez, María D; Gómez-Benito, Juana; Guilera, Georgina

    2016-01-01

    Short scales are typically used in the social, behavioural and health sciences. This is relevant since test length can influence whether items showing DIF are correctly flagged. This paper compares the relative effectiveness of discriminant logistic regression (DLR) and IRTLRDIF for detecting DIF in polytomous short tests. A simulation study was designed. Test length, sample size, DIF amount and item response categories number were manipulated. Type I error and power were evaluated. IRTLRDIF and DLR yielded Type I error rates close to nominal level in no-DIF conditions. Under DIF conditions, Type I error rates were affected by test length DIF amount, degree of test contamination, sample size and number of item response categories. DLR showed a higher Type I error rate than did IRTLRDIF. Power rates were affected by DIF amount and sample size, but not by test length. DLR achieved higher power rates than did IRTLRDIF in very short tests, although the high Type I error rate involved means that this result cannot be taken into account. Test length had an important impact on the Type I error rate. IRTLRDIF and DLR showed a low power rate in short tests and with small sample sizes.

  7. Building Numbers from Primes

    Science.gov (United States)

    Burkhart, Jerry

    2009-01-01

    Prime numbers are often described as the "building blocks" of natural numbers. This article shows how the author and his students took this idea literally by using prime factorizations to build numbers with blocks. In this activity, students explore many concepts of number theory, including the relationship between greatest common factors and…

  8. Introduction to number theory

    CERN Document Server

    Vazzana, Anthony; Garth, David

    2007-01-01

    One of the oldest branches of mathematics, number theory is a vast field devoted to studying the properties of whole numbers. Offering a flexible format for a one- or two-semester course, Introduction to Number Theory uses worked examples, numerous exercises, and two popular software packages to describe a diverse array of number theory topics.

  9. On the number of special numbers

    Indian Academy of Sciences (India)

    without loss of any generality to be the first k primes), then the equation a + b = c has .... This is an elementary exercise in partial summation (see [12]). Thus ... This is easily done by inserting a stronger form of the prime number theorem into the.

  10. Quantitative Analysis of Complex Multiple-Choice Items in Science Technology and Society: Item Scaling

    Directory of Open Access Journals (Sweden)

    Ángel Vázquez Alonso

    2005-05-01

    Full Text Available The scarce attention to assessment and evaluation in science education research has been especially harmful for Science-Technology-Society (STS education, due to the dialectic, tentative, value-laden, and controversial nature of most STS topics. To overcome the methodological pitfalls of the STS assessment instruments used in the past, an empirically developed instrument (VOSTS, Views on Science-Technology-Society have been suggested. Some methodological proposals, namely the multiple response models and the computing of a global attitudinal index, were suggested to improve the item implementation. The final step of these methodological proposals requires the categorization of STS statements. This paper describes the process of categorization through a scaling procedure ruled by a panel of experts, acting as judges, according to the body of knowledge from history, epistemology, and sociology of science. The statement categorization allows for the sound foundation of STS items, which is useful in educational assessment and science education research, and may also increase teachers’ self-confidence in the development of the STS curriculum for science classrooms.

  11. Maintenance of item and order information in verbal working memory.

    Science.gov (United States)

    Camos, Valérie; Lagner, Prune; Loaiza, Vanessa M

    2017-09-01

    Although verbal recall of item and order information is well-researched in short-term memory paradigms, there is relatively little research concerning item and order recall from working memory. The following study examined whether manipulating the opportunity for attentional refreshing and articulatory rehearsal in a complex span task differently affected the recall of item- and order-specific information of the memoranda. Five experiments varied the opportunity for articulatory rehearsal and attentional refreshing in a complex span task, but the type of recall was manipulated between experiments (item and order, order only, and item only recall). The results showed that impairing attentional refreshing and articulatory rehearsal similarly affected recall regardless of whether the scoring procedure (Experiments 1 and 4) or recall requirements (Experiments 2, 3, and 5) reflected item- or order-specific recall. This implies that both mechanisms sustain the maintenance of item and order information, and suggests that the common cumulative functioning of these two mechanisms to maintain items could be at the root of order maintenance.

  12. Group differences in the heritability of items and test scores

    NARCIS (Netherlands)

    Wicherts, J.M.; Johnson, W.

    2009-01-01

    It is important to understand potential sources of group differences in the heritability of intelligence test scores. On the basis of a basic item response model we argue that heritabilities which are based on dichotomous item scores normally do not generalize from one sample to the next. If groups

  13. The development of a single-item Food Choice Questionnaire

    NARCIS (Netherlands)

    Onwezen, M.C.; Reinders, M.J.; Verain, M.C.D.; Snoek, H.M.

    2019-01-01

    Based on the multi-item Food Choice Questionnaire (FCQ) originally developed by Steptoe and colleagues (1995), the current study developed a single-item FCQ that provides an acceptable balance between practical needs and psychometric concerns. Studies 1 (N = 1851) and 2 (2a (N = 3290), 2b (N =

  14. 41 CFR 109-1.5109 - Control of sensitive items.

    Science.gov (United States)

    2010-07-01

    ... administrative control of sensitive items assigned for general use within an organizational unit as appropriate... 41 Public Contracts and Property Management 3 2010-07-01 2010-07-01 false Control of sensitive...-INTRODUCTION 1.51-Personal Property Management Standards and Practices § 109-1.5109 Control of sensitive items...

  15. 17 CFR 229.1010 - (Item 1010) Financial statements.

    Science.gov (United States)

    2010-04-01

    ....1010 (Item 1010) Financial statements. (a) Financial information. Furnish the following financial information: (1) Audited financial statements for the two fiscal years required to be filed with the company's... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false (Item 1010) Financial...

  16. Item Construction and Psychometric Models Appropriate for Constructed Responses

    Science.gov (United States)

    1991-08-01

    which involve only one attribute per item. This is especially true when we are dealing with constructed-response items, we have to measure much more...Service University of Ilinois Educacional Testing Service Rosedal Road Capign. IL 61801 Princeton. K3 08541 Princeton. N3 08541 Dr. Charles LeiS Dr

  17. 17 CFR 229.406 - (Item 406) Code of ethics.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false (Item 406) Code of ethics. 229... 406) Code of ethics. (a) Disclose whether the registrant has adopted a code of ethics that applies to... code of ethics, explain why it has not done so. (b) For purposes of this Item 406, the term code of...

  18. Mathematical-programming approaches to test item pool design

    NARCIS (Netherlands)

    Veldkamp, Bernard P.; van der Linden, Willem J.; Ariel, A.

    2002-01-01

    This paper presents an approach to item pool design that has the potential to improve on the quality of current item pools in educational and psychological testing andhence to increase both measurement precision and validity. The approach consists of the application of mathematical programming

  19. Elu kui näitemäng / Helju Koger

    Index Scriptorium Estoniae

    Koger, Helju, 1943-

    2007-01-01

    VI kihelkonnapäevadest Juurus. Juuru Mihkli kirikus esines ansambel Resonabilis. Konverentsil räägiti Järlepa mõisast, Anu Allikvee pidas ettekande "August von Kotzebue elu nagu näitemäng" jm. Näitemängu "Pärmi Jaagu unenägu" nägi kohalike asjaarmastajate esituses

  20. Effects of Aging and IQ on Item and Associative Memory

    Science.gov (United States)

    Ratcliff, Roger; Thapar, Anjali; McKoon, Gail

    2011-01-01

    The effects of aging and IQ on performance were examined in 4 memory tasks: item recognition, associative recognition, cued recall, and free recall. For item and associative recognition, accuracy and the response time (RT) distributions for correct and error responses were explained by Ratcliff's (1978) diffusion model at the level of individual…

  1. The Influence of Item Properties on Association-Memory

    Science.gov (United States)

    Madan, Christopher R.; Glaholt, Mackenzie G.; Caplan, Jeremy B.

    2010-01-01

    Word properties like imageability and word frequency improve cued recall of verbal paired-associates. We asked whether these enhancements follow simply from prior effects on item-memory, or also strengthen associations between items. Participants studied word pairs varying in imageability or frequency: pairs were "pure" (high-high, low-low) or…

  2. 31 CFR 50.14 - Separate line item.

    Science.gov (United States)

    2010-07-01

    ....14 Money and Finance: Treasury Office of the Secretary of the Treasury TERRORISM RISK INSURANCE PROGRAM Disclosures as Conditions for Federal Payment § 50.14 Separate line item. An insurer is deemed to be in compliance with the requirement of providing disclosure on a “separate line item in the policy...

  3. Procedures for Selecting Items for Computerized Adaptive Tests.

    Science.gov (United States)

    Kingsbury, G. Gage; Zara, Anthony R.

    1989-01-01

    Several classical approaches and alternative approaches to item selection for computerized adaptive testing (CAT) are reviewed and compared. The study also describes procedures for constrained CAT that may be added to classical item selection approaches to allow them to be used for applied testing. (TJH)

  4. Negative Affect Impairs Associative Memory but Not Item Memory

    Science.gov (United States)

    Bisby, James A.; Burgess, Neil

    2014-01-01

    The formation of associations between items and their context has been proposed to rely on mechanisms distinct from those supporting memory for a single item. Although emotional experiences can profoundly affect memory, our understanding of how it interacts with different aspects of memory remains unclear. We performed three experiments to examine…

  5. Item response theory at subject- and group-level

    NARCIS (Netherlands)

    Tobi, Hilde

    1990-01-01

    This paper reviews the literature about item response models for the subject level and aggregated level (group level). Group-level item response models (IRMs) are used in the United States in large-scale assessment programs such as the National Assessment of Educational Progress and the California

  6. Repair systems with exchangeable items and the longest queue mechanism

    NARCIS (Netherlands)

    Ravid, R.; Boxma, O.J.; Perry, D.

    2013-01-01

    We consider a repair facility consisting of one repairman and two arrival streams of failed items, from bases 1 and 2. The arrival processes are independent Poisson processes, and the repair times are independent and identically exponentially distributed. The item types are exchangeable, and a

  7. Repair systems with exchangeable items and the longest queue mechanism

    NARCIS (Netherlands)

    Ravid, R.; Boxma, O.J.; Perry, D.

    2011-01-01

    We consider a repair facility consisting of one repairman and two arrival streams of failed items, from bases 1 and 2. The arrival processes are independent Poisson processes, and the repair times are independent and identically exponentially distributed. The item types are exchangeable, and a

  8. The Role of Item Feedback in Self-Adapted Testing.

    Science.gov (United States)

    Roos, Linda L.; And Others

    1997-01-01

    The importance of item feedback in self-adapted testing was studied by comparing feedback and no feedback conditions for computerized adaptive tests and self-adapted tests taken by 363 college students. Results indicate that item feedback is not necessary to realize score differences between self-adapted and computerized adaptive testing. (SLD)

  9. Characterizing Sources of Uncertainty in Item Response Theory Scale Scores

    Science.gov (United States)

    Yang, Ji Seung; Hansen, Mark; Cai, Li

    2012-01-01

    Traditional estimators of item response theory scale scores ignore uncertainty carried over from the item calibration process, which can lead to incorrect estimates of the standard errors of measurement (SEMs). Here, the authors review a variety of approaches that have been applied to this problem and compare them on the basis of their statistical…

  10. Practical Guide to Conducting an Item Response Theory Analysis

    Science.gov (United States)

    Toland, Michael D.

    2014-01-01

    Item response theory (IRT) is a psychometric technique used in the development, evaluation, improvement, and scoring of multi-item scales. This pedagogical article provides the necessary information needed to understand how to conduct, interpret, and report results from two commonly used ordered polytomous IRT models (Samejima's graded…

  11. Item Response Theory Modeling of the Philadelphia Naming Test

    Science.gov (United States)

    Fergadiotis, Gerasimos; Kellough, Stacey; Hula, William D.

    2015-01-01

    Purpose: In this study, we investigated the fit of the Philadelphia Naming Test (PNT; Roach, Schwartz, Martin, Grewal, & Brecher, 1996) to an item-response-theory measurement model, estimated the precision of the resulting scores and item parameters, and provided a theoretical rationale for the interpretation of PNT overall scores by relating…

  12. 48 CFR 53.212 - Acquisition of commercial items.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Acquisition of commercial... (CONTINUED) CLAUSES AND FORMS FORMS Prescription of Forms 53.212 Acquisition of commercial items. SF 1449 (Rev. 3/2005), Solicitation/Contract/Order for Commercial Items. SF 1449 is prescribed for use in...

  13. 48 CFR 52.212-2 - Evaluation-Commercial Items.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Evaluation-Commercial....212-2 Evaluation—Commercial Items. As prescribed in 12.301(c), the Contracting Officer may insert a provision substantially as follows: Evaluation—Commercial Items (JAN 1999) (a) The Government will award a...

  14. 48 CFR 46.202-1 - Contracts for commercial items.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Contracts for commercial... CONTRACT MANAGEMENT QUALITY ASSURANCE Contract Quality Requirements 46.202-1 Contracts for commercial items. When acquiring commercial items (see part 12), the Government shall rely on contractors' existing...

  15. Dissociation between source and item memory in Parkinson's disease

    Institute of Scientific and Technical Information of China (English)

    Hu Panpan; Li Youhai; Ma Huijuan; Xi Chunhua; Chen Xianwen; Wang Kai

    2014-01-01

    Background Episodic memory includes information about item memory and source memory.Many researches support the hypothesis that these two memory systems are implemented by different brain structures.The aim of this study was to investigate the characteristics of item memory and source memory processing in patients with Parkinson's disease (PD),and to further verify the hypothesis of dual-process model of source and item memory.Methods We established a neuropsychological battery to measure the performance of item memory and source memory.Totally 35 PD individuals and 35 matched healthy controls (HC) were administrated with the battery.Item memory task consists of the learning and recognition of high-frequency national Chinese characters; source memory task consists of the learning and recognition of three modes (character,picture,and image) of objects.Results Compared with the controls,the idiopathic PD patients have been impaired source memory (PD vs.HC:0.65±0.06 vs.0.72±0.09,P=0.001),but not impaired in item memory (PD vs.HC:0.65±0.07 vs.0.67±0.08,P=0.240).Conclusions The present experiment provides evidence for dissociation between item and source memory in PD patients,thereby strengthening the claim that the item or source memory rely on different brain structures.PD patients show poor source memory,in which dopamine plays a critical role.

  16. Semiparametric Item Response Functions in the Context of Guessing

    Science.gov (United States)

    Falk, Carl F.; Cai, Li

    2016-01-01

    We present a logistic function of a monotonic polynomial with a lower asymptote, allowing additional flexibility beyond the three-parameter logistic model. We develop a maximum marginal likelihood-based approach to estimate the item parameters. The new item response model is demonstrated on math assessment data from a state, and a computationally…

  17. Graphical modeling for item difficulty in medical faculty exams

    African Journals Online (AJOL)

    . Conclusion: The ... difficulty criteria. Key words: Item difficulty, quality control, statistical process control, variable control charts ..... assumed that 68% of the values fall in the interval ± 1.S; .... The balance of the construction of items of exam has ...

  18. A person fit test for IRT models for polytomous items

    NARCIS (Netherlands)

    Glas, Cornelis A.W.; Dagohoy, A.V.

    2007-01-01

    A person fit test based on the Lagrange multiplier test is presented for three item response theory models for polytomous items: the generalized partial credit model, the sequential model, and the graded response model. The test can also be used in the framework of multidimensional ability

  19. Bayes factor covariance testing in item response models

    NARCIS (Netherlands)

    Fox, J.P.; Mulder, J.; Sinharay, Sandip

    2017-01-01

    Two marginal one-parameter item response theory models are introduced, by integrating out the latent variable or random item parameter. It is shown that both marginal response models are multivariate (probit) models with a compound symmetry covariance structure. Several common hypotheses concerning

  20. Bayes Factor Covariance Testing in Item Response Models

    NARCIS (Netherlands)

    Fox, Jean-Paul; Mulder, Joris; Sinharay, Sandip

    2017-01-01

    Two marginal one-parameter item response theory models are introduced, by integrating out the latent variable or random item parameter. It is shown that both marginal response models are multivariate (probit) models with a compound symmetry covariance structure. Several common hypotheses concerning

  1. Optimizing incomplete sample designs for item response model parameters

    NARCIS (Netherlands)

    van der Linden, Willem J.

    Several models for optimizing incomplete sample designs with respect to information on the item parameters are presented. The following cases are considered: (1) known ability parameters; (2) unknown ability parameters; (3) item sets with multiple ability scales; and (4) response models with

  2. Algorithms for computerized test construction using classical item parameters

    NARCIS (Netherlands)

    Adema, Jos J.; van der Linden, Willem J.

    1989-01-01

    Recently, linear programming models for test construction were developed. These models were based on the information function from item response theory. In this paper another approach is followed. Two 0-1 linear programming models for the construction of tests using classical item and test

  3. LLWnotes - Volume 11, Number 3

    International Nuclear Information System (INIS)

    1996-04-01

    This document is the April 1996 issue of LLWnotes. It contains articles and news items on the following topics: news items related to states and compacts, Low-Level Radioactive Waste (LLW) Forum activities, and court rulings and calendars. State and compact items featured include Texas licensing procedures, renewal of Envirocare's license, and Ward Valley. Massachusetts Board suspension of some siting tasks and Massachusetts Court rules for US DOE regarding rebates are also reported

  4. An item response theory analysis of the Olweus Bullying scale.

    Science.gov (United States)

    Breivik, Kyrre; Olweus, Dan

    2014-12-02

    In the present article, we used IRT (graded response) modeling as a useful technology for a detailed and refined study of the psychometric properties of the various items of the Olweus Bullying scale and the scale itself. The sample consisted of a very large number of Norwegian 4th-10th grade students (n = 48 926). The IRT analyses revealed that the scale was essentially unidimensional and had excellent reliability in the upper ranges of the latent bullying tendency trait, as intended and desired. Gender DIF effects were identified with regard to girls' use of indirect bullying by social exclusion and boys' use of physical bullying by hitting and kicking but these effects were small and worked in opposite directions, having negligible effects at the scale level. Also scale scores adjusted for DIF effects differed very little from non-adjusted scores. In conclusion, the empirical data were well characterized by the chosen IRT model and the Olweus Bullying scale was considered well suited for the conduct of fair and reliable comparisons involving different gender-age groups. Information Aggr. Behav. 9999:XX-XX, 2014. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

  5. Factorial Structure and Age-Related Psychometrics of the MIDUS Personality Adjective Items across the Lifespan

    Science.gov (United States)

    Zimprich, Daniel; Allemand, Mathias; Lachman, Margie E.

    2014-01-01

    The present study addresses issues of measurement invariance and comparability of factor parameters of Big Five personality adjective items across age. Data from the Midlife in the United States (MIDUS) survey were used to investigate age-related developmental psychometrics of the MIDUS personality adjective items in two large cross-sectional samples (exploratory sample: N = 862; analysis sample: N = 3,000). After having established and replicated a comprehensive five-factor structure of the measure, increasing levels of measurement invariance were tested across ten age groups. Results indicate that the measure demonstrates strict measurement invariance in terms of number of factors and factor loadings. Also, we found that factor variances and covariances were equal across age groups. By contrast, a number of age-related factor mean differences emerged. The practical implications of these results are discussed and future research is suggested. PMID:21910548

  6. Selection of relevant items for decommissioning costing estimation of a PWR using fuzzy logic

    International Nuclear Information System (INIS)

    Monteiro, Deiglys Borges; Busse, Alexander Lucas; Moreira, Joao M.L.; Maiorino, Jose Rubens

    2015-01-01

    The decommissioning is an important part of a nuclear power plant life cycle which may occur by technical, economical or safety reasons. Decommissioning requires carrying out a large number of tasks that should be planned in advance, involves cost evaluations, preparation of plans of activity and actual operational actions. Despite the large number of tasks, only part of them is relevant for cost estimation purpose. The technical literature and international regulatory agencies suggest a variety of methods for decommissioning cost estimation. Most of them require a very detailed knowledge of the plant and data available suitable for plants that are starting their decommissioning but not for those in the planning stage. The present work aims to apply fuzzy logic to sort out relevant items to cost estimation in order to reduce the work effort involved. The scheme uses parametric equations for specific cost items, and is applied to specific parts of the process of nuclear power plant decommissioning. (author)

  7. Selection of relevant items for decommissioning costing estimation of a PWR using fuzzy logic

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Deiglys Borges; Busse, Alexander Lucas; Moreira, Joao M.L.; Maiorino, Jose Rubens, E-mail: deiglys.monteiro@ufabc.edu.br, E-mail: alexlucasb@gmail.com, E-mail: joao.moreira@ufabc.edu.br, E-mail: joserubens.maiorino@ufabc.edu.br [Universidade Federal do ABC (CECS/UFABC), Santo Andre, SP (Brazil). Centro de Engenharia, Modelagem e Ciencias Aplicadas. Programa de Pos-Graduacao em Energia e Engenharia da Energia

    2015-07-01

    The decommissioning is an important part of a nuclear power plant life cycle which may occur by technical, economical or safety reasons. Decommissioning requires carrying out a large number of tasks that should be planned in advance, involves cost evaluations, preparation of plans of activity and actual operational actions. Despite the large number of tasks, only part of them is relevant for cost estimation purpose. The technical literature and international regulatory agencies suggest a variety of methods for decommissioning cost estimation. Most of them require a very detailed knowledge of the plant and data available suitable for plants that are starting their decommissioning but not for those in the planning stage. The present work aims to apply fuzzy logic to sort out relevant items to cost estimation in order to reduce the work effort involved. The scheme uses parametric equations for specific cost items, and is applied to specific parts of the process of nuclear power plant decommissioning. (author)

  8. p-adic numbers

    OpenAIRE

    Grešak, Rozalija

    2015-01-01

    The field of real numbers is usually constructed using Dedekind cuts. In these thesis we focus on the construction of the field of real numbers using metric completion of rational numbers using Cauchy sequences. In a similar manner we construct the field of p-adic numbers, describe some of their basic and topological properties. We follow by a construction of complex p-adic numbers and we compare them with the ordinary complex numbers. We conclude the thesis by giving a motivation for the int...

  9. The Lexicographic Treatment of Sublexical and Multilexical Items in a Northern Sotho Monolingual Dictionary: A Challenge for Lexicographers

    Directory of Open Access Journals (Sweden)

    Motlokwe Clifford Mphahlele

    2011-10-01

    Full Text Available

    Abstract: Dictionaries have in the past used a word-based approach in which sublexical and multilexical items were not regarded as lemmata. Metalexicography as the theoretical component of lexicography requires that sublexical and multilexical items be lemmatized and treated as independent lemmata in the macrostructure of dictionaries. One of the greater challenges for compiling a better and user-oriented Northern Sotho monolingual dictionary is to treat sublexical and multi-lexical items as macrostructural elements. Treating these items, the lexicographer faces quite a number of challenges. This article proposes possible ways in which sublexical and multilexical elements could be successfully treated in a Northern Sotho monolingual dictionary. Taking stock of these challenges, the writer comes with suggestions that would assist lexicographers in the compi-lation of a user-friendly, lexicon-based monolingual dictionary that would lead users to successful information retrieval.

    Keywords: SUBLEXICAL ITEMS, MULTILEXICAL ITEMS, AFFIXES, PREFIXAL MOR-PHEMES, SUFFIXAL MORPHEMES, INTEGRATED MICROSTRUCTURE, WORD-BASED APPROACH, LEMMATIZATION, COLLOCATIONS, COMPOUNDS, COMPLEXES, GROUP PREPOSITIONS, FIXED EXPRESSIONS, MORPHEMES, METALEXICOGRAPHICAL ASPECTS, WORD-FORMATION PROCESSES, WORD-INTERNAL FUNCTION, USER-ORIENTED MONO-LINGUAL DICTIONARY, GRAMMAR, HOMONYMOUS LEMMA, POLYSEMOUS LEMMA, DECODING, ENCODING, SEMANTIC COMMENT, SEMANTIC TRANSPARENCY

    Opsomming: Die leksikografiese behandeling van subleksikale en multi-leksikale items in 'n Noord-Sotho- eentalige woordeboek: 'n Uitdaging vir leksikograwe. Woordeboeke het in die verlede 'n woordgebaseerde benadering gevolg waar-by subleksikale en multileksikale items nie as lemmas beskou is nie. Die metaleksikografie as die teoretiese komponent van die leksikografie vereis dat subleksikale en multileksikale items gelem-matiseer word en as onafhanklike lemmas in die makrostuktuur van woordeboeke

  10. On the number of special numbers

    Indian Academy of Sciences (India)

    We now apply the theory of the Thue equation to obtain an effective bound on m. Indeed, by Lemma 3.2, we can write m2 = ba3 and m2 − 4 = cd3 with b, c cubefree. By the above, both b, c are bounded since they are cubefree and all their prime factors are less than e63727. Now we have a finite number of. Thue equations:.

  11. Analysis of differential item functioning in the depression item bank from the Patient Reported Outcome Measurement Information System (PROMIS: An item response theory approach

    Directory of Open Access Journals (Sweden)

    JOSEPH P. EIMICKE

    2009-06-01

    Full Text Available The aims of this paper are to present findings related to differential item functioning (DIF in the Patient Reported Outcome Measurement Information System (PROMIS depression item bank, and to discuss potential threats to the validity of results from studies of DIF. The 32 depression items studied were modified from several widely used instruments. DIF analyses of gender, age and education were performed using a sample of 735 individuals recruited by a survey polling firm. DIF hypotheses were generated by asking content experts to indicate whether or not they expected DIF to be present, and the direction of the DIF with respect to the studied comparison groups. Primary analyses were conducted using the graded item response model (for polytomous, ordered response category data with likelihood ratio tests of DIF, accompanied by magnitude measures. Sensitivity analyses were performed using other item response models and approaches to DIF detection. Despite some caveats, the items that are recommended for exclusion or for separate calibration were "I felt like crying" and "I had trouble enjoying things that I used to enjoy." The item, "I felt I had no energy," was also flagged as evidencing DIF, and recommended for additional review. On the one hand, false DIF detection (Type 1 error was controlled to the extent possible by ensuring model fit and purification. On the other hand, power for DIF detection might have been compromised by several factors, including sparse data and small sample sizes. Nonetheless, practical and not just statistical significance should be considered. In this case the overall magnitude and impact of DIF was small for the groups studied, although impact was relatively large for some individuals.

  12. Geriatric Anxiety Scale: item response theory analysis, differential item functioning, and creation of a ten-item short form (GAS-10).

    Science.gov (United States)

    Mueller, Anne E; Segal, Daniel L; Gavett, Brandon; Marty, Meghan A; Yochim, Brian; June, Andrea; Coolidge, Frederick L

    2015-07-01

    The Geriatric Anxiety Scale (GAS; Segal et al. (Segal, D. L., June, A., Payne, M., Coolidge, F. L. and Yochim, B. (2010). Journal of Anxiety Disorders, 24, 709-714. doi:10.1016/j.janxdis.2010.05.002) is a self-report measure of anxiety that was designed to address unique issues associated with anxiety assessment in older adults. This study is the first to use item response theory (IRT) to examine the psychometric properties of a measure of anxiety in older adults. A large sample of older adults (n = 581; mean age = 72.32 years, SD = 7.64 years, range = 60 to 96 years; 64% women; 88% European American) completed the GAS. IRT properties were examined. The presence of differential item functioning (DIF) or measurement bias by age and sex was assessed, and a ten-item short form of the GAS (called the GAS-10) was created. All GAS items had discrimination parameters of 1.07 or greater. Items from the somatic subscale tended to have lower discrimination parameters than items on the cognitive or affective subscales. Two items were flagged for DIF, but the impact of the DIF was negligible. Women scored significantly higher than men on the GAS and its subscales. Participants in the young-old group (60 to 79 years old) scored significantly higher on the cognitive subscale than participants in the old-old group (80 years old and older). Results from the IRT analyses indicated that the GAS and GAS-10 have strong psychometric properties among older adults. We conclude by discussing implications and future research directions.

  13. Use of flawed multiple-choice items by the New England Journal of Medicine for continuing medical education.

    Science.gov (United States)

    Stagnaro-Green, Alex S; Downing, Steven M

    2006-09-01

    Physicians in the United States are required to complete a minimum number of continuing medical education (CME) credits annually. The goal of CME is to ensure that physicians maintain their knowledge and skills throughout their medical career. The New England Journal of Medicine (NEJM) provides its readers with the opportunity to obtain weekly CME credits. Deviation from established item-writing principles may result in a decrease in validity evidence for tests. This study evaluated the quality of 40 NEJM MCQs using the standard evidence-based principles of effective item writing. Each multiple-choice item reviewed had at least three item flaws, with a mean of 5.1 and a range of 3 to 7. The results of this study demonstrate that the NEJM uses flawed MCQs in its weekly CME program.

  14. Remembered but Unused: The Accessory Items in Working Memory that Do Not Guide Attention

    Science.gov (United States)

    Peters, Judith C.; Goebel, Rainer; Roelfsema, Pieter R.

    2009-01-01

    If we search for an item, a representation of this item in our working memory guides attention to matching items in the visual scene. We can hold multiple items in working memory. Do all these items guide attention in parallel? We asked participants to detect a target object in a stream of objects while they maintained a second item in memory for…

  15. Item Purification Does Not Always Improve DIF Detection: A Counterexample with Angoff's Delta Plot

    Science.gov (United States)

    Magis, David; Facon, Bruno

    2013-01-01

    Item purification is an iterative process that is often advocated as improving the identification of items affected by differential item functioning (DIF). With test-score-based DIF detection methods, item purification iteratively removes the items currently flagged as DIF from the test scores to get purified sets of items, unaffected by DIF. The…

  16. Fuzzy inventory model for deteriorating items, with time depended demand, shortages, and fully backlogging

    OpenAIRE

    Wasim Akram Mandal; Sahidul Islam

    2016-01-01

    In this paper analyzes fuzzy inventory system for deterioration item with time depended demand. Shortages are allowed under fully backlogged. Fixed cost, deterioration cost, shortages cost, holding cost are the cost considered in this model. Fuzziness is applying by allowing the cost components (holding cost, deterioration, shortage cost, holding cost, etc). In fuzzy environment it considered all required parameter to be triangular fuzzy numbers. One numerical solution of the model is obtaine...

  17. The medial temporal lobes distinguish between within-item and item-context relations during autobiographical memory retrieval.

    Science.gov (United States)

    Sheldon, Signy; Levine, Brian

    2015-12-01

    During autobiographical memory retrieval, the medial temporal lobes (MTL) relate together multiple event elements, including object (within-item relations) and context (item-context relations) information, to create a cohesive memory. There is consistent support for a functional specialization within the MTL according to these relational processes, much of which comes from recognition memory experiments. In this study, we compared brain activation patterns associated with retrieving within-item relations (i.e., associating conceptual and sensory-perceptual object features) and item-context relations (i.e., spatial relations among objects) with respect to naturalistic autobiographical retrieval. We developed a novel paradigm that cued participants to retrieve information about past autobiographical events, non-episodic within-item relations, and non-episodic item-context relations with the perceptuomotor aspects of retrieval equated across these conditions. We used multivariate analysis techniques to extract common and distinct patterns of activity among these conditions within the MTL and across the whole brain, both in terms of spatial and temporal patterns of activity. The anterior MTL (perirhinal cortex and anterior hippocampus) was preferentially recruited for generating within-item relations later in retrieval whereas the posterior MTL (posterior parahippocampal cortex and posterior hippocampus) was preferentially recruited for generating item-context relations across the retrieval phase. These findings provide novel evidence for functional specialization within the MTL with respect to naturalistic memory retrieval. © 2015 Wiley Periodicals, Inc.

  18. 41 CFR 101-26.605 - Items other than petroleum products and electronic items available from the Defense Logistics...

    Science.gov (United States)

    2010-07-01

    ... petroleum products and electronic items available from the Defense Logistics Agency. 101-26.605 Section 101... available from the Defense Logistics Agency. Agencies required to use GSA supply sources should also use... Logistics Agency, the catalog will contain only those items in Federal supply classification classes which...

  19. Modeling Item-Level and Step-Level Invariance Effects in Polytomous Items Using the Partial Credit Model

    Science.gov (United States)

    Gattamorta, Karina A.; Penfield, Randall D.; Myers, Nicholas D.

    2012-01-01

    Measurement invariance is a common consideration in the evaluation of the validity and fairness of test scores when the tested population contains distinct groups of examinees, such as examinees receiving different forms of a translated test. Measurement invariance in polytomous items has traditionally been evaluated at the item-level,…

  20. Mixture Item Response Theory-MIMIC Model: Simultaneous Estimation of Differential Item Functioning for Manifest Groups and Latent Classes

    Science.gov (United States)

    Bilir, Mustafa Kuzey

    2009-01-01

    This study uses a new psychometric model (mixture item response theory-MIMIC model) that simultaneously estimates differential item functioning (DIF) across manifest groups and latent classes. Current DIF detection methods investigate DIF from only one side, either across manifest groups (e.g., gender, ethnicity, etc.), or across latent classes…

  1. Number projection method

    International Nuclear Information System (INIS)

    Kaneko, K.

    1987-01-01

    A relationship between the number projection and the shell model methods is investigated in the case of a single-j shell. We can find a one-to-one correspondence between the number projected and the shell model states

  2. Numbers and brains.

    Science.gov (United States)

    Gallistel, C R

    2017-12-01

    The representation of discrete and continuous quantities appears to be ancient and pervasive in animal brains. Because numbers are the natural carriers of these representations, we may discover that in brains, it's numbers all the way down.

  3. Neutralisation and binding of VHS virus by monovalent antibody fragments

    DEFF Research Database (Denmark)

    Cupit, P.M.; Lorenzen, Niels; Strachan, G.

    2001-01-01

    We have previously reported the cloning and characterisation of the heavy and light chain variable domain genes encoding three monoclonal antibodies (Mabs) that bind viral haemorrhagic septicaemia virus (VHSV). Two of these antibodies, 3F1H10 and 3F1A2 both neutralised the virus though 3F1A2...... appeared to recognise a broader range of virus isolates. The variable domains of these two antibodies differ by only four residues (Lorenzen et al., 2000a. Fish Shellfish Immunol. 10, 129-142). To further study the mechanism of neutralisation, Fab fragments as well as a series of recombinant bacterial...... single chain antibody (scAb) fragments were generated from the three anti-VHSV Mabs and their variable domain genes, respectively. Fabs and scAbs derived from the neutralising Mabs were both able to neutralise the VHSV type 1 isolate DK-F1. In addition, a series of scAb fragments were produced using...

  4. Optimization of Design and Planing VHS Building Using Chronolux

    Directory of Open Access Journals (Sweden)

    Beta Paramita

    2016-09-01

    Full Text Available Gedebage integrated vocational high school (SMK is a school which accommodates the concept of technopolis. The school has four programs: building engineering, family welfare education (PKK/food service, mechanical engineering, and tourism - which produce skilled and ready-to-work graduates. This article aims to recommend the sun exposure toward the building of the school, which is related to site planning and design strategies based on the duration of solar radiation on vegetation, and building facades as well as the distance between buildings through the use of Chronolux plug-in on Sketch-up Software. From the measurement, it is found that vegetation can reduce sky view factors (SVF from 76.4 to 38.87%. For the building façade, it is able to reduce sun exposure from 4 hours 51 minutes to 3 hours 19 minutes with SVF from 47.26 to 38.11%. Meanwhile, the building distance of 9 m receives sun exposure from 9:00 am to 3.42 pm.

  5. Number in Dinka

    DEFF Research Database (Denmark)

    Andersen, Torben

    2014-01-01

    had a marked singular and an unmarked plural. Synchronically, however, the singular is arguably the basic member of the number category as revealed by the use of the two numbers. In addition, some nouns have a collective form, which is grammatically singular. Number also plays a role...

  6. Safety-in-numbers

    DEFF Research Database (Denmark)

    Elvik, Rune; Bjørnskau, Torkel

    2017-01-01

    Highlights •26 studies of the safety-in-numbers effect are reviewed. •The existence of a safety-in-numbers effect is confirmed. •Results are consistent. •Causes of the safety-in-numbers effect are incompletely known....

  7. Discovery: Prime Numbers

    Science.gov (United States)

    de Mestre, Neville

    2008-01-01

    Prime numbers are important as the building blocks for the set of all natural numbers, because prime factorisation is an important and useful property of all natural numbers. Students can discover them by using the method known as the Sieve of Eratosthenes, named after the Greek geographer and astronomer who lived from c. 276-194 BC. Eratosthenes…

  8. Criticality Safety Support to a Project Addressing SNM Legacy Items at LLNL

    International Nuclear Information System (INIS)

    Pearson, J S; Burch, J G; Dodson, K E; Huang, S T

    2005-01-01

    The programmatic, facility and criticality safety support staffs at the LLNL Plutonium Facility worked together to successfully develop and implement a project to process legacy (DNFSB Recommendation 94-1 and non-Environmental, Safety, and Health (ES and H) labeled) materials in storage. Over many years, material had accumulated in storage that lacked information to adequately characterize the material for current criticality safety controls used in the facility. Generally, the fissionable material mass information was well known, but other information such as form, impurities, internal packaging, and presence of internal moderating or reflecting materials were not well documented. In many cases, the material was excess to programmatic need, but such a determination was difficult with the little information given on MC and A labels and in the MC and A database. The material was not packaged as efficiently as possible, so it also occupied much more valuable storage space than was necessary. Although safe as stored, the inadequately characterized material posed a risk for criticality safety noncompliances if moved within the facility under current criticality safety controls. A Legacy Item Implementation Plan was developed and implemented to deal with this problem. Reasonable bounding conditions were determined for the material involved, and criticality safety evaluations were completed. Two appropriately designated glove boxes were identified and criticality safety controls were developed to safely inspect the material. Inspecting the material involved identifying containers of legacy material, followed by opening, evaluating, processing if necessary, characterizing and repackaging the material. Material from multiple containers was consolidated more efficiently thus decreasing the total number of stored items to about one half of the highest count. Current packaging requirements were implemented. Detailed characterization of the material was captured in databases

  9. Instemmingsgeneigdheid en verskillende item- en responsformate in 'n gesommeerde selfbeoordelingskaal

    Directory of Open Access Journals (Sweden)

    Nadene Hanekom

    1998-06-01

    Full Text Available This study examines the degree of acquiescence present when the item and response formats of a summated rating scale are varied. It is often recommended that acquiescence response bias in rating scales may be controlled by using both positively and negatively worded items. Such items are generally worded in the Likert-type format of statements. The purpose of the study was to establish whether items in question format would result in a smaller degree of acquiescence than items worded as statements. the response format was also varied (five- and seven-point options to determine whether this would influence the reliability and degree of acquiescence in the scales. A twenty-item Locus of Control (LC questionnaire was used, but each item was complemented by its opposite, resulting in 40 items. The subjects, divided randomly into two groups, were second year students who had to complete four versions of the questionnaire, plus a shortened version of Bass's scale for measuring acquiescence. The LC version were questions or statements each combined with a five- or seven-point respons format. Partial counterbalancing was introduced by testing on two separate occasions, presenting the tests to the two groups in the opposite order. The degree of acquiescence was assessed by correlating the items with their opposite, and by correlating scores on each version with scores on the acquiescence questionnaire. No major difference were found between the various item and response format in relation to acquiescence. Opsomming Hierdie ondersoek is uitgevoer om te bepaal of die mate van instemmingsgeneigdheid deur die item- en responsformaat van 'n gesommeerde selfbeoordelingskaal beinvloed word. Daar word dikwels aanbeveel dat die gebruik van positief- sowel as negatiefbewoorde items in 'n vraelys instemmingsgeneigdheid beperk. Suike items word gewoonlik in die tradisionele Likertformaat as stellings geformuleer. Die doel van die ondersoek was om te bepaal of items

  10. Macrostructural Treatment of Multi-word Lexical Items

    Directory of Open Access Journals (Sweden)

    Alenka Vrbinc

    2011-05-01

    Full Text Available The paper discusses the macrostructural treatment of multi-word lexical items in mono- and bilingual dictionaries. First, the classification of multi-word lexical items is presented, and special attention is paid to the discussion of compounds – a specific group of multi-word lexical items that is most commonly afforded headword status but whose inclusion in the headword list may also depend on spelling. Then the inclusion of multi-word lexical items in monolingual dictionaries is dealt with in greater detail, while the results of a short survey on the inclusion of five randomly chosen multi-word lexical items in seven English monolingual dictionaries are presented. The proposals as to how to treat these five multi-word lexical items in bilingual dictionaries are presented in the section about the inclusion of multi-word lexical items in bilingual dictionaries. The conclusion is that it is most important to take the users’ needs into consideration and to make any dictionary as user friendly as possible.

  11. Can Item Keyword Feedback Help Remediate Knowledge Gaps?

    Science.gov (United States)

    Feinberg, Richard A; Clauser, Amanda L

    2016-10-01

    In graduate medical education, assessment results can effectively guide professional development when both assessment and feedback support a formative model. When individuals cannot directly access the test questions and responses, a way of using assessment results formatively is to provide item keyword feedback. The purpose of the following study was to investigate whether exposure to item keyword feedback aids in learner remediation. Participants included 319 trainees who completed a medical subspecialty in-training examination (ITE) in 2012 as first-year fellows, and then 1 year later in 2013 as second-year fellows. Performance on 2013 ITE items in which keywords were, or were not, exposed as part of the 2012 ITE score feedback was compared across groups based on the amount of time studying (preparation). For the same items common to both 2012 and 2013 ITEs, response patterns were analyzed to investigate changes in answer selection. Test takers who indicated greater amounts of preparation on the 2013 ITE did not perform better on the items in which keywords were exposed compared to those who were not exposed. The response pattern analysis substantiated overall growth in performance from the 2012 ITE. For items with incorrect responses on both attempts, examinees selected the same option 58% of the time. Results from the current study were unsuccessful in supporting the use of item keywords in aiding remediation. Unfortunately, the results did provide evidence of examinees retaining misinformation.

  12. Economic production quantity concerning learning and the reworking of imperfect items

    Directory of Open Access Journals (Sweden)

    Tsai Deng-Maw

    2012-01-01

    Full Text Available The classical economic production quantity (EPQ model assumes that items produced are of perfect quality and the production rate is constant. However, production quality depends on the condition of the process. Due to process deterioration or other factors, the production process may shift and produce imperfect quality items. These imperfect quality items sometimes can be reworked and repaired; hence, overall production-inventory costs can be reduced significantly. In addition, it can be found in practice that the time or cost required to repetitively produce a unit of a product decreases when the number of units produced by a worker or a group of workers increases. Under this circumstance, the unit production cost cannot be regarded as constant and, therefore, cannot be ignored when taking account of the total cost. This paper incorporates the effects of learning and the reworking of defective items on the EPQ model since they were not considered in existing models. An optimal operation policy that minimizes the expected total cost per unit time is derived. A numerical example is provided to illustrate the proposed model. In addition, sensitivity analysis is performed and discussed.

  13. Examining Multiple Sources of Differential Item Functioning on the Clinician & Group CAHPS® Survey

    Science.gov (United States)

    Rodriguez, Hector P; Crane, Paul K

    2011-01-01

    Objective To evaluate psychometric properties of a widely used patient experience survey. Data Sources English-language responses to the Clinician & Group Consumer Assessment of Healthcare Providers and Systems (CG-CAHPS®) survey (n = 12,244) from a 2008 quality improvement initiative involving eight southern California medical groups. Methods We used an iterative hybrid ordinal logistic regression/item response theory differential item functioning (DIF) algorithm to identify items with DIF related to patient sociodemographic characteristics, duration of the physician–patient relationship, number of physician visits, and self-rated physical and mental health. We accounted for all sources of DIF and determined its cumulative impact. Principal Findings The upper end of the CG-CAHPS® performance range is measured with low precision. With sensitive settings, some items were found to have DIF. However, overall DIF impact was negligible, as 0.14 percent of participants had salient DIF impact. Latinos who spoke predominantly English at home had the highest prevalence of salient DIF impact at 0.26 percent. Conclusions The CG-CAHPS® functions similarly across commercially insured respondents from diverse backgrounds. Consequently, previously documented racial and ethnic group differences likely reflect true differences rather than measurement bias. The impact of low precision at the upper end of the scale should be clarified. PMID:22092021

  14. Identifying Sources of Scientific Knowledge: classifying non-source items in the WoS

    Energy Technology Data Exchange (ETDEWEB)

    Calero-Medina, C.M.

    2016-07-01

    The sources of scientific knowledge can be tracked using the references in scientific publications. For instance, the publications from the scientific journals covered by the Web of Science database (WoS) contain references to publications for which an indexed source record exist in the WoS (source items) or to references for which an indexed source record does not exist in the WoS (non-source items). The classification of the non-source items is the main objective of the work in progress presented here. Some other scholars have classified and identified non-source items with different purposes (e.g. Butler & Visser (2006); Liseé, Larivière & Archambault (2008); Nerderhof, van Leeuwen & van Raan (2010); Hicks & Wang (2013); Boyack & Klavans (2014)). But these studies are focused in specific source types, fields or set of papers. The work presented here is much broader in terms of the number of publications, source types and fields. (Author)

  15. Comparing children's Homo sapiens and chimpanzees' Pan troglodytes quantity judgments of sequentially presented sets of items

    Directory of Open Access Journals (Sweden)

    Michael J. BERAN, Julie S. JOHNSON-PYNN, Christopher READY

    2011-08-01

    Full Text Available We presented a quantity judgment task that involved comparing two sequentially presented sets of items to preschoolers and chimpanzees using nearly identical procedures that excluded verbal instructions to children. Trial difficulty in this task reflected the ratio difference between sets of discrete items where larger ratios (e.g., 0.80 as from comparing 4 to 5 were more difficult than smaller ones (e.g., 0.50 as from comparing 4 to 8. Children also completed verbal-based tasks probing the relationship between counting proficiency and performance on the quantity judgment task of sequentially presented identical sized items. Both species’ performance was best when ratios between comparison sets were small regardless of set size in all types of tasks. Generally, chimpanzees and older children performed better than younger children except at larger ratios. Children’s counting proficiency was not related to success in choosing the larger of two quantities of identical-sized items. These results indicate that chimpanzees and children share an approximate number sense that is reflected through analog magnitude estimation when comparing quantities [Current Zoology 57 (4: 419–428, 2011].

  16. Serial recall, word frequency, and mixed lists: the influence of item arrangement.

    Science.gov (United States)

    Miller, Leonie M; Roodenrys, Steven

    2012-11-01

    Studies of the effect of word frequency in the serial recall task show that lists of high-frequency words are better recalled than lists of low-frequency words; however, when high- and low-frequency words are alternated within a list, there is no difference in the level of recall for the two types of words, and recall is intermediate between lists of pure frequency. This pattern has been argued to arise from the development of a network of activated long-term representations of list items that support the redintegration of all list items in a nondirectional and nonspecific way. More recently, it has been proposed that the frequency effect might be a product of the coarticulation of items at word boundaries and their influence on rehearsal rather than a consequence of memory representations. The current work examines recall performance in mixed lists of an equal number of high- and low-frequency items arranged in contiguous segments (i.e., HHHLLL and LLLHHH), under quiet and articulatory suppression conditions, to test whether the effect is (a) nondirectional and (b) dependent on articulatory processes. These experiments demonstrate that neither explanation is satisfactory, although the results suggest that the effect is mnemonic. A language-based approach to short-term memory is favored with emphasis on the role of speech production processes at output.

  17. Robust Measurement via A Fused Latent and Graphical Item Response Theory Model.

    Science.gov (United States)

    Chen, Yunxiao; Li, Xiaoou; Liu, Jingchen; Ying, Zhiliang

    2018-03-12

    Item response theory (IRT) plays an important role in psychological and educational measurement. Unlike the classical testing theory, IRT models aggregate the item level information, yielding more accurate measurements. Most IRT models assume local independence, an assumption not likely to be satisfied in practice, especially when the number of items is large. Results in the literature and simulation studies in this paper reveal that misspecifying the local independence assumption may result in inaccurate measurements and differential item functioning. To provide more robust measurements, we propose an integrated approach by adding a graphical component to a multidimensional IRT model that can offset the effect of unknown local dependence. The new model contains a confirmatory latent variable component, which measures the targeted latent traits, and a graphical component, which captures the local dependence. An efficient proximal algorithm is proposed for the parameter estimation and structure learning of the local dependence. This approach can substantially improve the measurement, given no prior information on the local dependence structure. The model can be applied to measure both a unidimensional latent trait and multidimensional latent traits.

  18. Science Literacy: How do High School Students Solve PISA Test Items?

    Science.gov (United States)

    Wati, F.; Sinaga, P.; Priyandoko, D.

    2017-09-01

    The Programme for International Students Assessment (PISA) does assess students’ science literacy in a real-life contexts and wide variety of situation. Therefore, the results do not provide adequate information for the teacher to excavate students’ science literacy because the range of materials taught at schools depends on the curriculum used. This study aims to investigate the way how junior high school students in Indonesia solve PISA test items. Data was collected by using PISA test items in greenhouse unit employed to 36 students of 9th grade. Students’ answer was analyzed qualitatively for each item based on competence tested in the problem. The way how students answer the problem exhibits their ability in particular competence which is influenced by a number of factors. Those are students’ unfamiliarity with test construction, low performance on reading, low in connecting available information and question, and limitation on expressing their ideas effectively and easy-read. As the effort, selected PISA test items can be used in accordance teaching topic taught to familiarize students with science literacy.

  19. Asymptotic numbers: Pt.1

    International Nuclear Information System (INIS)

    Todorov, T.D.

    1980-01-01

    The set of asymptotic numbers A as a system of generalized numbers including the system of real numbers R, as well as infinitely small (infinitesimals) and infinitely large numbers, is introduced. The detailed algebraic properties of A, which are unusual as compared with the known algebraic structures, are studied. It is proved that the set of asymptotic numbers A cannot be isomorphically embedded as a subspace in any group, ring or field, but some particular subsets of asymptotic numbers are shown to be groups, rings, and fields. The algebraic operation, additive and multiplicative forms, and the algebraic properties are constructed in an appropriate way. It is shown that the asymptotic numbers give rise to a new type of generalized functions quite analogous to the distributions of Schwartz allowing, however, the operation multiplication. A possible application of these functions to quantum theory is discussed

  20. Applied number theory

    CERN Document Server

    Niederreiter, Harald

    2015-01-01

    This textbook effectively builds a bridge from basic number theory to recent advances in applied number theory. It presents the first unified account of the four major areas of application where number theory plays a fundamental role, namely cryptography, coding theory, quasi-Monte Carlo methods, and pseudorandom number generation, allowing the authors to delineate the manifold links and interrelations between these areas.  Number theory, which Carl-Friedrich Gauss famously dubbed the queen of mathematics, has always been considered a very beautiful field of mathematics, producing lovely results and elegant proofs. While only very few real-life applications were known in the past, today number theory can be found in everyday life: in supermarket bar code scanners, in our cars’ GPS systems, in online banking, etc.  Starting with a brief introductory course on number theory in Chapter 1, which makes the book more accessible for undergraduates, the authors describe the four main application areas in Chapters...

  1. Mediate gamma radiation effects on some packaged food items

    International Nuclear Information System (INIS)

    Inamura, Patricia Y.; Uehara, Vanessa B.; Teixeira, Christian A.H.M.; Mastro, Nelida L. del

    2012-01-01

    For most of prepackaged foods a 10 kGy radiation dose is considered the maximum dose needed; however, the commercially available and practically accepted packaging materials must be suitable for such application. This work describes the application of ionizing radiation on several packaged food items, using 5 dehydrated food items, 5 ready-to-eat meals and 5 ready-to-eat food items irradiated in a 60 Co gamma source with a 3 kGy dose. The quality evaluation of the irradiated samples was performed 2 and 8 months after irradiation. Microbiological analysis (bacteria, fungus and yeast load) was performed. The sensory characteristics were established for appearance, aroma, texture and flavor attributes were also established. From these data, the acceptability of all irradiated items was obtained. All ready-to-eat food items assayed like manioc flour, some pâtés and blocks of raw brown sugar and most of ready-to-eat meals like sausages and chicken with legumes were considered acceptable for microbial and sensory characteristics. On the other hand, the dehydrated food items chosen for this study, such as dehydrated bacon potatoes or pea soups were not accepted by the sensory analysis. A careful dose choice and special irradiation conditions must be used in order to achieve sensory acceptability needed for the commercialization of specific irradiated food items. - Highlights: ► We applied gamma radiation on several kinds of packaged food items. ► Microbiological and sensory analyses were performed 2 and 8 months after irradiation. ► All ready-to-eat food items assayed were approved for microbial and sensory characteristics. ► Most ready-to-eat meals like sausages and chicken with legumes were also acceptable. ► Dehydrated bacon potatoes or pea soups were considered not acceptable.

  2. Item-saving assessment of self-care performance in children with developmental disabilities: A prospective caregiver-report computerized adaptive test

    Science.gov (United States)

    Chen, Cheng-Te; Chen, Yu-Lan; Lin, Yu-Ching; Hsieh, Ching-Lin; Tzeng, Jeng-Yi

    2018-01-01

    Objective The purpose of this study was to construct a computerized adaptive test (CAT) for measuring self-care performance (the CAT-SC) in children with developmental disabilities (DD) aged from 6 months to 12 years in a content-inclusive, precise, and efficient fashion. Methods The study was divided into 3 phases: (1) item bank development, (2) item testing, and (3) a simulation study to determine the stopping rules for the administration of the CAT-SC. A total of 215 caregivers of children with DD were interviewed with the 73-item CAT-SC item bank. An item response theory model was adopted for examining the construct validity to estimate item parameters after investigation of the unidimensionality, equality of slope parameters, item fitness, and differential item functioning (DIF). In the last phase, the reliability and concurrent validity of the CAT-SC were evaluated. Results The final CAT-SC item bank contained 56 items. The stopping rules suggested were (a) reliability coefficient greater than 0.9 or (b) 14 items administered. The results of simulation also showed that 85% of the estimated self-care performance scores would reach a reliability higher than 0.9 with a mean test length of 8.5 items, and the mean reliability for the rest was 0.86. Administering the CAT-SC could reduce the number of items administered by 75% to 84%. In addition, self-care performances estimated by the CAT-SC and the full item bank were very similar to each other (Pearson r = 0.98). Conclusion The newly developed CAT-SC can efficiently measure self-care performance in children with DD whose performances are comparable to those of TD children aged from 6 months to 12 years as precisely as the whole item bank. The item bank of the CAT-SC has good reliability and a unidimensional self-care construct, and the CAT can estimate self-care performance with less than 25% of the items in the item bank. Therefore, the CAT-SC could be useful for measuring self-care performance in children with

  3. Application of the Commercial Grade Item (CGI) Dedication Process for Procurement of Nuclear Safety Related Items at Nuclear Power Plant Krsko (NEK)

    International Nuclear Information System (INIS)

    Heruc, Z.; Pozar, J.

    1998-01-01

    CGI procurement is a process whereby parts are brought without imposing Appendix B Quality Assurance requirements on the supplier, and than dedicated for use in safety-related applications. The dedication process involves 1) based upon required safety function, an engineering evaluation to identify critical characteristic of the item and specification of acceptance criteria; and 2) quality control activities to ensure the item(s) supplied meets the acceptance criteria specified. CGI Dedication supports the supply of certified components/parts for the plant operation in an environment where the number of nuclear qualified suppliers diminishes. It requires a more active role of the plant personnel, therefore presenting an additional burden on human resources, but at the same time increases the technical KNOW-HOW and improves the confidence of test and inspection data presented in the certificates. Very often it is also cost beneficial. This paper is a continuation to last year presentation of the introduction of this method into NEK's procurement process and presents the current approach and some practical examples. (author)

  4. Identifying predictors of physics item difficulty: A linear regression approach

    Science.gov (United States)

    Mesic, Vanes; Muratovic, Hasnija

    2011-06-01

    Large-scale assessments of student achievement in physics are often approached with an intention to discriminate students based on the attained level of their physics competencies. Therefore, for purposes of test design, it is important that items display an acceptable discriminatory behavior. To that end, it is recommended to avoid extraordinary difficult and very easy items. Knowing the factors that influence physics item difficulty makes it possible to model the item difficulty even before the first pilot study is conducted. Thus, by identifying predictors of physics item difficulty, we can improve the test-design process. Furthermore, we get additional qualitative feedback regarding the basic aspects of student cognitive achievement in physics that are directly responsible for the obtained, quantitative test results. In this study, we conducted a secondary analysis of data that came from two large-scale assessments of student physics achievement at the end of compulsory education in Bosnia and Herzegovina. Foremost, we explored the concept of “physics competence” and performed a content analysis of 123 physics items that were included within the above-mentioned assessments. Thereafter, an item database was created. Items were described by variables which reflect some basic cognitive aspects of physics competence. For each of the assessments, Rasch item difficulties were calculated in separate analyses. In order to make the item difficulties from different assessments comparable, a virtual test equating procedure had to be implemented. Finally, a regression model of physics item difficulty was created. It has been shown that 61.2% of item difficulty variance can be explained by factors which reflect the automaticity, complexity, and modality of the knowledge structure that is relevant for generating the most probable correct solution, as well as by the divergence of required thinking and interference effects between intuitive and formal physics knowledge

  5. Identifying predictors of physics item difficulty: A linear regression approach

    Directory of Open Access Journals (Sweden)

    Hasnija Muratovic

    2011-06-01

    Full Text Available Large-scale assessments of student achievement in physics are often approached with an intention to discriminate students based on the attained level of their physics competencies. Therefore, for purposes of test design, it is important that items display an acceptable discriminatory behavior. To that end, it is recommended to avoid extraordinary difficult and very easy items. Knowing the factors that influence physics item difficulty makes it possible to model the item difficulty even before the first pilot study is conducted. Thus, by identifying predictors of physics item difficulty, we can improve the test-design process. Furthermore, we get additional qualitative feedback regarding the basic aspects of student cognitive achievement in physics that are directly responsible for the obtained, quantitative test results. In this study, we conducted a secondary analysis of data that came from two large-scale assessments of student physics achievement at the end of compulsory education in Bosnia and Herzegovina. Foremost, we explored the concept of “physics competence” and performed a content analysis of 123 physics items that were included within the above-mentioned assessments. Thereafter, an item database was created. Items were described by variables which reflect some basic cognitive aspects of physics competence. For each of the assessments, Rasch item difficulties were calculated in separate analyses. In order to make the item difficulties from different assessments comparable, a virtual test equating procedure had to be implemented. Finally, a regression model of physics item difficulty was created. It has been shown that 61.2% of item difficulty variance can be explained by factors which reflect the automaticity, complexity, and modality of the knowledge structure that is relevant for generating the most probable correct solution, as well as by the divergence of required thinking and interference effects between intuitive and formal

  6. Item-Based Top-N Recommendation Algorithms

    Science.gov (United States)

    2003-01-20

    basket of items, utilized by many e-commerce sites, cannot take advantage of pre-computed user-to-user similarities. Finally, even though the...not discriminate between items that are present in frequent itemsets and items that are not, while still maintaining the computational advantages of...453219 0.02% 7.74 ccard 42629 68793 398619 0.01% 9.35 ecommerce 6667 17491 91222 0.08% 13.68 em 8002 1648 769311 5.83% 96.14 ml 943 1682 100000 6.31

  7. Use of commercial grade item dedication to reduce procurement costs

    International Nuclear Information System (INIS)

    Rosch, F.

    1995-01-01

    In the mid-1980s, the Nuclear Regulatory Industry (NRC) began inspecting utility practices of procuring and dedicating commercial grade items intended for plant safety-related applications. As a result of the industry efforts to address NRC concerns, nuclear utilities have enhanced existing programs and procedures for dedication of commercial grade items. Though these programs were originally enhanced to meet NRC concerns, utilities have discovered that the dedication of commercial grade items can also reduce overall procurement costs. This paper will discuss the enhancement of utility dedication programs and demonstrates how utilities have utilized them to reduce procurement costs

  8. QA in the procurement of items and services

    International Nuclear Information System (INIS)

    Wilhelm, H.

    1980-01-01

    Procurement of items and services is one of the important elements during the design and construction of Nuclear Power Plants. The purchaser has to establish and implement controls over the procurement process to ensure that the quality criteria, quality level and other quality requirements specified for the particuliar item or service are taken into account. The effect on safety of an error in service or the malfunction of an item is the most important factor to be considered in determining the extent of quality assurance efforts. A typical example of a procurement process will be demonstrated for safety related mechanical components. (orig./RW)

  9. Irradiation processing of food items for exports

    International Nuclear Information System (INIS)

    Sareen, Shashi

    1998-01-01

    Globalization has led to rapid increases in international food trade. About 460 million metric tonnes of foodstuffs are traded annually of a value to the order of 300 billion US dollar. With such high trade figures, it is imperative to provide safe and nutritious foods to consumers and to minimize food losses due to spoilage. Food irradiation is a technology which has been under study and debate since fifties for the purpose of food preservation. This technology has been extensively reviewed and studied at international levels and by several countries and on the basis of these, a number of countries have permitted the use of irradiation for specified foods and are also applying it on commercial scale. In this paper, a review of the status and importance of this technology has been brought out to include the application of the technology and its perceived benefits, acceptance of the technology at the international level and by different countries including the scenario in India, the various types of concerns expressed by Governments as well as consumers and specific areas with regard to exports for which the technology would be beneficial. (author)

  10. P2-19: The Effect of item Repetition on Item-Context Association Depends on the Prior Exposure of Items

    Directory of Open Access Journals (Sweden)

    Hongmi Lee

    2012-10-01

    Full Text Available Previous studies have reported conflicting findings on whether item repetition has beneficial or detrimental effects on source memory. To reconcile such contradictions, we investigated whether the degree of pre-exposure of items can be a potential modulating factor. The experimental procedures spanned two consecutive days. On Day 1, participants were exposed to a set of unfamiliar faces. On Day 2, the same faces presented on the previous day were used again in half of the participants, whereas novel faces were used for the other half. Day 2 procedures consisted of three successive phases: item repetition, source association, and source memory test. In the item repetition phase, half of the face stimuli were repeatedly presented while participants were making male/female judgments. During the source association phase, both the repeated and the unrepeated faces appeared in one of the four locations on the screen. Finally, participants were tested on the location in which a given face was presented during the previous phase and reported the confidence of their memory. Source memory accuracy was measured as the percentage of correct non-guess trials. As results, we found a significant interaction between prior exposure and repetition. Repetition impaired source memory when the items had been pre-exposed on Day 1, while it led to greater accuracy in novel ones. These results show that pre-experimental exposure can modulate the effects of repetition on associative binding between an item and its contextual information, suggesting that pre-existing representation and novelty signal interact to form new episodic memory.

  11. Why item parcels are (almost) never appropriate: two wrongs do not make a right--camouflaging misspecification with item parcels in CFA models.

    Science.gov (United States)

    Marsh, Herbert W; Lüdtke, Oliver; Nagengast, Benjamin; Morin, Alexandre J S; Von Davier, Matthias

    2013-09-01

    The present investigation has a dual focus: to evaluate problematic practice in the use of item parcels and to suggest exploratory structural equation models (ESEMs) as a viable alternative to the traditional independent clusters confirmatory factor analysis (ICM-CFA) model (with no cross-loadings, subsidiary factors, or correlated uniquenesses). Typically, it is ill-advised to (a) use item parcels when ICM-CFA models do not fit the data, and (b) retain ICM-CFA models when items cross-load on multiple factors. However, the combined use of (a) and (b) is widespread and often provides such misleadingly good fit indexes that applied researchers might believe that misspecification problems are resolved--that 2 wrongs really do make a right. Taking a pragmatist perspective, in 4 studies we demonstrate with responses to the Rosenberg Self-Esteem Inventory (Rosenberg, 1965), Big Five personality factors, and simulated data that even small cross-loadings seriously distort relations among ICM-CFA constructs or even decisions on the number of factors; although obvious in item-level analyses, this is camouflaged by the use of parcels. ESEMs provide a viable alternative to ICM-CFAs and a test for the appropriateness of parcels. The use of parcels with an ICM-CFA model is most justifiable when the fit of both ICM-CFA and ESEM models is acceptable and equally good, and when substantively important interpretations are similar. However, if the ESEM model fits the data better than the ICM-CFA model, then the use of parcels with an ICM-CFA model typically is ill-advised--particularly in studies that are also interested in scale development, latent means, and measurement invariance.

  12. Memory for Items and Relationships among Items Embedded in Realistic Scenes: Disproportionate Relational Memory Impairments in Amnesia

    Science.gov (United States)

    Hannula, Deborah E.; Tranel, Daniel; Allen, John S.; Kirchhoff, Brenda A.; Nickel, Allison E.; Cohen, Neal J.

    2014-01-01

    Objective The objective of this study was to examine the dependence of item memory and relational memory on medial temporal lobe (MTL) structures. Patients with amnesia, who either had extensive MTL damage or damage that was relatively restricted to the hippocampus, were tested, as was a matched comparison group. Disproportionate relational memory impairments were predicted for both patient groups, and those with extensive MTL damage were also expected to have impaired item memory. Method Participants studied scenes, and were tested with interleaved two-alternative forced-choice probe trials. Probe trials were either presented immediately after the corresponding study trial (lag 1), five trials later (lag 5), or nine trials later (lag 9) and consisted of the studied scene along with a manipulated version of that scene in which one item was replaced with a different exemplar (item memory test) or was moved to a new location (relational memory test). Participants were to identify the exact match of the studied scene. Results As predicted, patients were disproportionately impaired on the test of relational memory. Item memory performance was marginally poorer among patients with extensive MTL damage, but both groups were impaired relative to matched comparison participants. Impaired performance was evident at all lags, including the shortest possible lag (lag 1). Conclusions The results are consistent with the proposed role of the hippocampus in relational memory binding and representation, even at short delays, and suggest that the hippocampus may also contribute to successful item memory when items are embedded in complex scenes. PMID:25068665

  13. Predicting Lotto Numbers

    DEFF Research Database (Denmark)

    Jørgensen, Claus Bjørn; Suetens, Sigrid; Tyran, Jean-Robert

    numbers based on recent drawings. While most players pick the same set of numbers week after week without regards of numbers drawn or anything else, we find that those who do change, act on average in the way predicted by the law of small numbers as formalized in recent behavioral theory. In particular......We investigate the “law of small numbers” using a unique panel data set on lotto gambling. Because we can track individual players over time, we can measure how they react to outcomes of recent lotto drawings. We can therefore test whether they behave as if they believe they can predict lotto......, on average they move away from numbers that have recently been drawn, as suggested by the “gambler’s fallacy”, and move toward numbers that are on streak, i.e. have been drawn several weeks in a row, consistent with the “hot hand fallacy”....

  14. Invitation to number theory

    CERN Document Server

    Ore, Oystein

    2017-01-01

    Number theory is the branch of mathematics concerned with the counting numbers, 1, 2, 3, … and their multiples and factors. Of particular importance are odd and even numbers, squares and cubes, and prime numbers. But in spite of their simplicity, you will meet a multitude of topics in this book: magic squares, cryptarithms, finding the day of the week for a given date, constructing regular polygons, pythagorean triples, and many more. In this revised edition, John Watkins and Robin Wilson have updated the text to bring it in line with contemporary developments. They have added new material on Fermat's Last Theorem, the role of computers in number theory, and the use of number theory in cryptography, and have made numerous minor changes in the presentation and layout of the text and the exercises.

  15. The adventure of numbers

    CERN Document Server

    Godefroy, Gilles

    2004-01-01

    Numbers are fascinating. The fascination begins in childhood, when we first learn to count. It continues as we learn arithmetic, algebra, geometry, and so on. Eventually, we learn that numbers not only help us to measure the world, but also to understand it and, to some extent, to control it. In The Adventure of Numbers, Gilles Godefroy follows the thread of our expanding understanding of numbers to lead us through the history of mathematics. His goal is to share the joy of discovering and understanding this great adventure of the mind. The development of mathematics has been punctuated by a n

  16. Predicting Lotto Numbers

    DEFF Research Database (Denmark)

    Suetens, Sigrid; Galbo-Jørgensen, Claus B.; Tyran, Jean-Robert Karl

    2016-01-01

    We investigate the ‘law of small numbers’ using a data set on lotto gambling that allows us to measure players’ reactions to draws. While most players pick the same set of numbers week after week, we find that those who do change react on average as predicted by the law of small numbers...... as formalized in recent behavioral theory. In particular, players tend to bet less on numbers that have been drawn in the preceding week, as suggested by the ‘gambler’s fallacy’, and bet more on a number if it was frequently drawn in the recent past, consistent with the ‘hot-hand fallacy’....

  17. Beurling generalized numbers

    CERN Document Server

    Diamond, Harold G; Cheung, Man Ping

    2016-01-01

    "Generalized numbers" is a multiplicative structure introduced by A. Beurling to study how independent prime number theory is from the additivity of the natural numbers. The results and techniques of this theory apply to other systems having the character of prime numbers and integers; for example, it is used in the study of the prime number theorem (PNT) for ideals of algebraic number fields. Using both analytic and elementary methods, this book presents many old and new theorems, including several of the authors' results, and many examples of extremal behavior of g-number systems. Also, the authors give detailed accounts of the L^2 PNT theorem of J. P. Kahane and of the example created with H. L. Montgomery, showing that additive structure is needed for proving the Riemann hypothesis. Other interesting topics discussed are propositions "equivalent" to the PNT, the role of multiplicative convolution and Chebyshev's prime number formula for g-numbers, and how Beurling theory provides an interpretation of the ...

  18. Intuitive numbers guide decisions

    Directory of Open Access Journals (Sweden)

    Ellen Peters

    2008-12-01

    Full Text Available Measuring reaction times to number comparisons is thought to reveal a processing stage in elementary numerical cognition linked to internal, imprecise representations of number magnitudes. These intuitive representations of the mental number line have been demonstrated across species and human development but have been little explored in decision making. This paper develops and tests hypotheses about the influence of such evolutionarily ancient, intuitive numbers on human decisions. We demonstrate that individuals with more precise mental-number-line representations are higher in numeracy (number skills consistent with previous research with children. Individuals with more precise representations (compared to those with less precise representations also were more likely to choose larger, later amounts over smaller, immediate amounts, particularly with a larger proportional difference between the two monetary outcomes. In addition, they were more likely to choose an option with a larger proportional but smaller absolute difference compared to those with less precise representations. These results are consistent with intuitive number representations underlying: a perceived differences between numbers, b the extent to which proportional differences are weighed in decisions, and, ultimately, c the valuation of decision options. Human decision processes involving numbers important to health and financial matters may be rooted in elementary, biological processes shared with other species.

  19. Numbers, sequences and series

    CERN Document Server

    Hirst, Keith

    1994-01-01

    Number and geometry are the foundations upon which mathematics has been built over some 3000 years. This book is concerned with the logical foundations of number systems from integers to complex numbers. The author has chosen to develop the ideas by illustrating the techniques used throughout mathematics rather than using a self-contained logical treatise. The idea of proof has been emphasised, as has the illustration of concepts from a graphical, numerical and algebraic point of view. Having laid the foundations of the number system, the author has then turned to the analysis of infinite proc

  20. Purchases of Consumable Items Transferred to the Defense Logistics Agency

    National Research Council Canada - National Science Library

    Young, Shelton

    1995-01-01

    Defense Management Report Decision 926, "Consolidation of Inventory Control Points," included a recommendation to transfer all consumable items managed by the Military Departments to the Defense Logistics Agency (DLA...

  1. Storage options for Long Length Contaminated Equipment (LLCE) items

    International Nuclear Information System (INIS)

    Hodgson, R.D.

    1994-11-01

    A review of the Washington state requirements for the storage of long equipment items removed from tanks indicate that if the contaminated materials on the long equipment items are analyzed and determined to be DW, and not EHW, the containers can be stored on an uncovered, RCRA approved, storage pad. Long equipment items contaminated with reportable levels of EHW, or suspected of being contaminated with EHW, must be protected from the elements by means of a building or other protective covering that otherwise allows adequate inspection of the containers. Storage of the long equipment item containers on an uncovered storage pad is recommended and will reduce construction costs for new storage by an estimated 60 percent when compared to construction costs for enclosed storage

  2. 47 CFR 36.224 - Extraordinary items-Account 7600.

    Science.gov (United States)

    2010-10-01

    ..., REVENUES, EXPENSES, TAXES AND RESERVES FOR TELECOMMUNICATIONS COMPANIES 1 Operating Revenues and Certain... account of an operating nature are apportioned on a basis consistent with the nature of these items. ...

  3. Etendatakse 10-aastase kirjamehe näitemäng

    Index Scriptorium Estoniae

    2003-01-01

    Tartu katoliku kooli 3. klassi poisi Mario Raitari näitemäng "Kristoph Silvester von Tenderi lugu", mis on esimene lugu sarjast "Mario Raitari kroonika". Näidendit etendab Linnupuu Lastepereteatri trupp

  4. Consumable Item Transfer, Phase 2, Cash Imbalance Issue

    National Research Council Canada - National Science Library

    1997-01-01

    We are providing this report for your information and use. The Deputy Secretary of Defense directed the transfer of the management of consumable items to the Defense Logistics Agency (DLA) in July 1990...

  5. 17 CFR 229.402 - (Item 402) Executive compensation.

    Science.gov (United States)

    2010-04-01

    ... which its securities are listed or traded. (2) All compensation covered. This Item requires clear... different currency, a footnote must be provided to identify that currency and describe the rate and...

  6. Item-Based Top-N Recommendation Algorithms

    National Research Council Canada - National Science Library

    Deshpande, Mukund; Karypis, George

    2003-01-01

    ... items that will be of interest to a certain user. User-based collaborative filtering is the most successful technology for building recommender systems to date, and is extensively used in many commercial recommender systems...

  7. Evaluation of Item-Based Top-N Recommendation Algorithms

    National Research Council Canada - National Science Library

    Karypis, George

    2000-01-01

    ... items that will be of interest to a certain user. User-based Collaborative filtering is the most successful technology for building recommender systems to date, and is extensively used in many commercial recommender systems...

  8. 41 CFR 101-28.306-6 - Sensitive items.

    Science.gov (United States)

    2010-07-01

    ... Regulations System FEDERAL PROPERTY MANAGEMENT REGULATIONS SUPPLY AND PROCUREMENT 28-STORAGE AND DISTRIBUTION... accountable item of personal property. Each customer activity shall take all appropriate measures necessary to... Government use. ...

  9. Basic Stand Alone Medicare DME Line Items PUF

    Data.gov (United States)

    U.S. Department of Health & Human Services — This release contains the Basic Stand Alone (BSA) Durable Medical Equipment (DME) Line Items Public Use Files (PUF) with information from Medicare DME claims. The...

  10. Analyzing force concept inventory with item response theory

    Science.gov (United States)

    Wang, Jing; Bao, Lei

    2010-10-01

    Item response theory is a popular assessment method used in education. It rests on the assumption of a probability framework that relates students' innate ability and their performance on test questions. Item response theory transforms students' raw test scores into a scaled proficiency score, which can be used to compare results obtained with different test questions. The scaled score also addresses the issues of ceiling effects and guessing, which commonly exist in quantitative assessment. We used item response theory to analyze the force concept inventory (FCI). Our results show that item response theory can be useful for analyzing physics concept surveys such as the FCI and produces results about the individual questions and student performance that are beyond the capability of classical statistics. The theory yields detailed measurement parameters regarding the difficulty, discrimination features, and probability of correct guess for each of the FCI questions.

  11. 47 CFR 76.985 - Subscriber bill itemization.

    Science.gov (United States)

    2010-10-01

    ...) The amount of the total bill assessed as a franchise fee and the identity of the franchising authority... fees and costs itemized pursuant to this section. (c) Local franchising authorities may adopt...

  12. Creating a Database for Test Items in National Examinations (pp ...

    African Journals Online (AJOL)

    Nekky Umera

    different programmers create files and application programs over a long period. .... In theory or essay questions, alternative methods of solving problems are explored and ... Unworthy items are those that do not focus on the central concept or.

  13. Food items and general condition of Hyperopisus bebe occidentalis ...

    African Journals Online (AJOL)

    GREG

    2017-07-20

    Jul 20, 2017 ... Key words: Food items, Hyperopisus bebe occidentalis, Warri River, condition factor. ... Sufficient food intake aids optimal growth in fish, resulting ... It covers a surface area of 255 km2 with ... examination was carried out.

  14. Answering Fixed Response Items in Chemistry: A Pilot Study.

    Science.gov (United States)

    Hateley, R. J.

    1979-01-01

    Presents a pilot study on student thinking in chemistry. Verbal comments of a group of six college students were recorded and analyzed to identify how each student arrives at the correct answer in fixed response items in chemisty. (HM)

  15. Development of six PROMIS pediatrics proxy-report item banks.

    Science.gov (United States)

    Irwin, Debra E; Gross, Heather E; Stucky, Brian D; Thissen, David; DeWitt, Esi Morgan; Lai, Jin Shei; Amtmann, Dagmar; Khastou, Leyla; Varni, James W; DeWalt, Darren A

    2012-02-22

    Pediatric self-report should be considered the standard for measuring patient reported outcomes (PRO) among children. However, circumstances exist when the child is too young, cognitively impaired, or too ill to complete a PRO instrument and a proxy-report is needed. This paper describes the development process including the proxy cognitive interviews and large-field-test survey methods and sample characteristics employed to produce item parameters for the Patient Reported Outcomes Measurement Information System (PROMIS) pediatric proxy-report item banks. The PROMIS pediatric self-report items were converted into proxy-report items before undergoing cognitive interviews. These items covered six domains (physical function, emotional distress, social peer relationships, fatigue, pain interference, and asthma impact). Caregivers (n = 25) of children ages of 5 and 17 years provided qualitative feedback on proxy-report items to assess any major issues with these items. From May 2008 to March 2009, the large-scale survey enrolled children ages 8-17 years to complete the self-report version and caregivers to complete the proxy-report version of the survey (n = 1548 dyads). Caregivers of children ages 5 to 7 years completed the proxy report survey (n = 432). In addition, caregivers completed other proxy instruments, PedsQL™ 4.0 Generic Core Scales Parent Proxy-Report version, PedsQL™ Asthma Module Parent Proxy-Report version, and KIDSCREEN Parent-Proxy-52. Item content was well understood by proxies and did not require item revisions but some proxies clearly noted that determining an answer on behalf of their child was difficult for some items. Dyads and caregivers of children ages 5-17 years old were enrolled in the large-scale testing. The majority were female (85%), married (70%), Caucasian (64%) and had at least a high school education (94%). Approximately 50% had children with a chronic health condition, primarily asthma, which was diagnosed or treated within 6

  16. Development of six PROMIS pediatrics proxy-report item banks

    Directory of Open Access Journals (Sweden)

    Irwin Debra E

    2012-02-01

    Full Text Available Abstract Background Pediatric self-report should be considered the standard for measuring patient reported outcomes (PRO among children. However, circumstances exist when the child is too young, cognitively impaired, or too ill to complete a PRO instrument and a proxy-report is needed. This paper describes the development process including the proxy cognitive interviews and large-field-test survey methods and sample characteristics employed to produce item parameters for the Patient Reported Outcomes Measurement Information System (PROMIS pediatric proxy-report item banks. Methods The PROMIS pediatric self-report items were converted into proxy-report items before undergoing cognitive interviews. These items covered six domains (physical function, emotional distress, social peer relationships, fatigue, pain interference, and asthma impact. Caregivers (n = 25 of children ages of 5 and 17 years provided qualitative feedback on proxy-report items to assess any major issues with these items. From May 2008 to March 2009, the large-scale survey enrolled children ages 8-17 years to complete the self-report version and caregivers to complete the proxy-report version of the survey (n = 1548 dyads. Caregivers of children ages 5 to 7 years completed the proxy report survey (n = 432. In addition, caregivers completed other proxy instruments, PedsQL™ 4.0 Generic Core Scales Parent Proxy-Report version, PedsQL™ Asthma Module Parent Proxy-Report version, and KIDSCREEN Parent-Proxy-52. Results Item content was well understood by proxies and did not require item revisions but some proxies clearly noted that determining an answer on behalf of their child was difficult for some items. Dyads and caregivers of children ages 5-17 years old were enrolled in the large-scale testing. The majority were female (85%, married (70%, Caucasian (64% and had at least a high school education (94%. Approximately 50% had children with a chronic health condition, primarily

  17. Automated addition of Chelex solution to tubes containing trace items

    DEFF Research Database (Denmark)

    Stangegaard, Michael; Hansen, Thomas Møller; Hansen, Anders Johannes

    2011-01-01

    Extraction of DNA from trace items for forensic genetic DNA typing using a manual Chelex based extraction protocol requires addition of Chelex solution to sample tubes containing trace items. Automated of addition of Chelex solution may be hampered by high viscosity of the solution and fast...... sedimentation rate of the Chelex beads. Here, we present a simple method that can be used on an Eppendorf epMotion liquid handler resolving these issues...

  18. Directed forgetting of complex pictures in an item method paradigm

    OpenAIRE

    Hauswald, Anne; Kissler, Johanna

    2008-01-01

    An item-cued directed forgetting paradigm was used to investigate the ability to control episodic memory and selectively encode complex coloured pictures. A series of photographs was presented to 21 participants who were instructed to either remember or forget each picture after it was presented. Memory performance was later tested with a recognition task where all presented items had to be retrieved, regardless of the initial instructions. A directed forgetting effect that is, better recogni...

  19. The european emergency number 112 - the questionnaire

    OpenAIRE

    Goniewicz Krzysztof; Goniewicz Mariusz; Misztal Okońska Patrycja; Witold Pawłowski; Czerski Robert

    2017-01-01

    Goniewicz Krzysztof, Goniewicz Mariusz, Misztal Okońska Patrycja, Witold Pawłowski, Czerski Robert. The european emergency number 112 - the questionnaire. Journal of Education, Health and Sport. 2017;7(7):1165-1174. eISSN 2391-8306. DOI http://dx.doi.org/10.5281/zenodo.1117736 http://ojs.ukw.edu.pl/index.php/johs/article/view/5134 The journal has had 7 points in Ministry of Science and Higher Education parametric evaluation. Part B item 1223 (26.01....

  20. Promoting cold-start items in recommender systems.

    Science.gov (United States)

    Liu, Jin-Hu; Zhou, Tao; Zhang, Zi-Ke; Yang, Zimo; Liu, Chuang; Li, Wei-Min

    2014-01-01

    As one of the major challenges, cold-start problem plagues nearly all recommender systems. In particular, new items will be overlooked, impeding the development of new products online. Given limited resources, how to utilize the knowledge of recommender systems and design efficient marketing strategy for new items is extremely important. In this paper, we convert this ticklish issue into a clear mathematical problem based on a bipartite network representation. Under the most widely used algorithm in real e-commerce recommender systems, the so-called item-based collaborative filtering, we show that to simply push new items to active users is not a good strategy. Interestingly, experiments on real recommender systems indicate that to connect new items with some less active users will statistically yield better performance, namely, these new items will have more chance to appear in other users' recommendation lists. Further analysis suggests that the disassortative nature of recommender systems contributes to such observation. In a word, getting in-depth understanding on recommender systems could pave the way for the owners to popularize their cold-start products with low costs.

  1. MMPI-2 Item Endorsements in Dissociative Identity Disorder vs. Simulators.

    Science.gov (United States)

    Brand, Bethany L; Chasson, Gregory S; Palermo, Cori A; Donato, Frank M; Rhodes, Kyle P; Voorhees, Emily F

    2016-03-01

    Elevated scores on some MMPI-2 (Minnesota Multiphasic Inventory-2) validity scales are common among patients with dissociative identity disorder (DID), which raises questions about the validity of their responses. Such patients show elevated scores on atypical answers (F), F-psychopathology (Fp), atypical answers in the second half of the test (FB), schizophrenia (Sc), and depression (D) scales, with Fp showing the greatest utility in distinguishing them from coached and uncoached DID simulators. In the current study, we investigated the items on the MMPI-2 F, Fp, FB, Sc, and D scales that were most and least commonly endorsed by participants with DID in our 2014 study and compared these responses with those of coached and uncoached DID simulators. The comparisons revealed that patients with DID most frequently endorsed items related to dissociation, trauma, depression, fearfulness, conflict within family, and self-destructiveness. The coached group more successfully imitated item endorsements of the DID group than did the uncoached group. However, both simulating groups, especially the uncoached group, frequently endorsed items that were uncommonly endorsed by the DID group. The uncoached group endorsed items consistent with popular media portrayals of people with DID being violent, delusional, and unlawful. These results suggest that item endorsement patterns can provide useful information to clinicians making determinations about whether an individual is presenting with DID or feigning. © 2016 American Academy of Psychiatry and the Law.

  2. Combining item and bulk material loss-detection uncertainties

    International Nuclear Information System (INIS)

    Eggers, R.F.

    1982-01-01

    Loss detection requirements, such as five formula kilograms with 99% probability of detection, which apply to the sum of losses from material in both item and bulk form, constitute a special problem for the nuclear material statistician. Requirements of this type are included in the Material Control and Accounting Reform Amendments described in the Advance Notice of Proposed Rule Making (Federal Register, 46(175):45144-46151). Attribute test sampling of items is the method used to detect gross defects in the inventory of items in a given control unit. Attribute sampling plans are designed to detect a loss of a specificed goal quantity of material with a given probability. In contrast to the methods and statistical models used for item loss detection, bulk material loss detection requires all the material entering and leaving a control unit to be measured and the calculation of a loss estimator that will be tested against an appropriate alarm threshold. The alarm threshold is determined from an estimate of the error inherent in the components of the loss estimator. In this paper a simple grahical method of evaluating the combined capabilities of bulk material loss detection methods and item attribute testing procedures will be described. Quantitative results will be given for several cases, indicating how a decrease in the precision of the item loss detection method tends to force an increase in the precision of the bulk loss detection procedure in order to meet the overall detection requirement. 4 figures

  3. The Body Appreciation Scale-2: item refinement and psychometric evaluation.

    Science.gov (United States)

    Tylka, Tracy L; Wood-Barcalow, Nichole L

    2015-01-01

    Considered a positive body image measure, the 13-item Body Appreciation Scale (BAS; Avalos, Tylka, & Wood-Barcalow, 2005) assesses individuals' acceptance of, favorable opinions toward, and respect for their bodies. While the BAS has accrued psychometric support, we improved it by rewording certain BAS items (to eliminate sex-specific versions and body dissatisfaction-based language) and developing additional items based on positive body image research. In three studies, we examined the reworded, newly developed, and retained items to determine their psychometric properties among college and online community (Amazon Mechanical Turk) samples of 820 women and 767 men. After exploratory factor analysis, we retained 10 items (five original BAS items). Confirmatory factor analysis upheld the BAS-2's unidimensionality and invariance across sex and sample type. Its internal consistency, test-retest reliability, and construct (convergent, incremental, and discriminant) validity were supported. The BAS-2 is a psychometrically sound positive body image measure applicable for research and clinical settings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Promoting Cold-Start Items in Recommender Systems

    Science.gov (United States)

    Liu, Jin-Hu; Zhou, Tao; Zhang, Zi-Ke; Yang, Zimo; Liu, Chuang; Li, Wei-Min

    2014-01-01

    As one of the major challenges, cold-start problem plagues nearly all recommender systems. In particular, new items will be overlooked, impeding the development of new products online. Given limited resources, how to utilize the knowledge of recommender systems and design efficient marketing strategy for new items is extremely important. In this paper, we convert this ticklish issue into a clear mathematical problem based on a bipartite network representation. Under the most widely used algorithm in real e-commerce recommender systems, the so-called item-based collaborative filtering, we show that to simply push new items to active users is not a good strategy. Interestingly, experiments on real recommender systems indicate that to connect new items with some less active users will statistically yield better performance, namely, these new items will have more chance to appear in other users' recommendation lists. Further analysis suggests that the disassortative nature of recommender systems contributes to such observation. In a word, getting in-depth understanding on recommender systems could pave the way for the owners to popularize their cold-start products with low costs. PMID:25479013

  5. Analysis of Chemical Composition of Non-Ferrous Metal Items from the Ananyino Burial Ground

    Directory of Open Access Journals (Sweden)

    Saprykina Irina А.

    2016-03-01

    Full Text Available The article presents results of an analysis conducted by the authors in order to study chemical composition of items from non-ferrous metals found on the Ananyino burial ground. A number of research methods, including OES, XRF and TXRF was applied to study a selection of 387 samples of arrow- and spearheads, celts, tail-pieces, warhammers, poleaxes, knives and daggers, as well as items of attire and jewelry, some sporadic details of harness and bridle. The fi ndings are quite comparable. The results were classifi ed by the geochemical principle of 1,0% alloyage threshold. It was found out that the sample primarily consists of copper items, including “pure” copper and copper with a wide range of trace elements (particularly, Ni, As, Sb. The core (48% consists of copper items with traces of antimony and arsenic, or “pure” copper (7%, tin or triple bronze (40%; it also includes some other types of alloys based on copper or silver (5%. As the analysis has shown, complex ores seem to be the most probable source of copper. Traditionally, the Urals, the Sayan and the Altay Mountains, Kazakhstan and the Northern Caucasus were regarded as the most probable minefi elds to supply ores to the barren regions of Eastern Europe. While ore sources for products made of metallurgical “pure” copper are localized within the Ural mining and metallurgical region, metal sources for items cast from different groups of alloys (rather than imports of ready-made products require further research.

  6. Templates, Numbers & Watercolors.

    Science.gov (United States)

    Clemesha, David J.

    1990-01-01

    Describes how a second-grade class used large templates to draw and paint five-digit numbers. The lesson integrated artistic knowledge and vocabulary with their mathematics lesson in place value. Students learned how draftspeople use templates, and they studied number paintings by Charles Demuth and Jasper Johns. (KM)

  7. The 1992 Pacific Northwest Residential Energy Survey : Phase 1 : Book 4 : Item-by-item Crosstabulations.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration. End-Use Research Section; Applied Management & Planning Group (Firm)

    1993-06-01

    This book constitutes a portion of the primary documentation for the 1992 Pacific Northwest Residential Energy Survey, Phase I. The complete 33-volume set of primary documentation provides information needed by energy analysts and interpreters with respect to planning, execution, data collection, and data management of the PNWRES92-I process. Thirty of these volumes are devoted to different ``views`` of the data themselves, with each view having a special purpose or interest as its focus. Analyses and interpretations of these data will be the subjects of forthcoming publications. Conducted during the late summer and fall months of 1992, PNWRES92-I had the over-arching goal of satisfying basic requirements for a variety of information about the stock of residential units in Bonneville`s service region. Surveys with a similar goal were conducted in 1979 and 1983. This volume discerns the information by state. ``Selected crosstabulations`` refers to a set of nine survey items of wide interest (Dwelling Type, Ownership Type, Year-of-Construction, Dwelling Size, Primary Space-Heating Fuel, Primary Water-Heating Fuel, Household Income for 1991, Utility Type, and Space-Heating Fuels: Systems and Equipment) that were crosstabulated among themselves.

  8. Evaluation of the Hospital Anxiety and Depression Scale (HADS) in screening stroke patients for symptoms: Item Response Theory (IRT) analysis.

    Science.gov (United States)

    Ayis, Salma A; Ayerbe, Luis; Ashworth, Mark; DA Wolfe, Charles

    2018-03-01

    Variations have been reported in the number of underlying constructs and choice of thresholds that determine caseness of anxiety and /or depression using the Hospital Anxiety and Depression scale (HADS). This study examined the properties of each item of HADS as perceived by stroke patients, and assessed the information these items convey about anxiety and depression between 3 months to 5 years after stroke. The study included 1443 stroke patients from the South London Stroke Register (SLSR). The dimensionality of HADS was examined using factor analysis methods, and items' properties up to 5 years after stroke were tested using Item Response Theory (IRT) methods, including graded response models (GRMs). The presence of two dimensions of HADS (anxiety and depression) for stroke patients was confirmed. Items that accurately inferred about the severity of anxiety and depression, and offered good discrimination of caseness were identified as "I can laugh and see the funny side of things" (Q4) and "I get sudden feelings of panic" (Q13), discrimination 2.44 (se = 0.26), and 3.34 (se = 0.35), respectively. Items that shared properties, hence replicate inference were: "I get a sort of frightened feeling as if something awful is about to happen" (Q3), "I get a sort of frightened feeling like butterflies in my stomach" (Q6), and "Worrying thoughts go through my mind" (Q9). Item properties were maintained over time. Approximately 20% of patients were lost to follow up. A more concise selection of items based on their properties, would provide a precise approach for screening patients and for an optimal allocation of patients into clinical trials. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Readability and Comprehension of the Geriatric Depression Scale and PROMIS® Physical Function Items in Older African Americans and Latinos.

    Science.gov (United States)

    Paz, Sylvia H; Jones, Loretta; Calderón, José L; Hays, Ron D

    2017-02-01

    Depression and physical function are particularly important health domains for the elderly. The Geriatric Depression Scale (GDS) and the Patient-Reported Outcomes Measurement Information System (PROMIS ® ) physical function item bank are two surveys commonly used to measure these domains. It is unclear if these two instruments adequately measure these aspects of health in minority elderly. The aim of this study was to estimate the readability of the GDS and PROMIS ® physical function items and to assess their comprehensibility using a sample of African American and Latino elderly. Readability was estimated using the Flesch-Kincaid and Flesch Reading Ease (FRE) formulae for English versions, and a Spanish adaptation of the FRE formula for the Spanish versions. Comprehension of the GDS and PROMIS ® items by minority elderly was evaluated with 30 cognitive interviews. Readability estimates of a number of items in English and Spanish of the GDS and PROMIS ® physical functioning items exceed the U.S. recommended 5th-grade threshold for vulnerable populations, or were rated as 'fairly difficult', 'difficult', or 'very difficult' to read. Cognitive interviews revealed that many participants felt that more than the two (yes/no) GDS response options were needed to answer the questions. Wording of several PROMIS ® items was considered confusing, and interpreting responses was problematic because they were based on using physical aids. Problems with item wording and response options of the GDS and PROMIS ® physical function items may reduce reliability and validity of measurement when used with minority elderly.

  10. Few items in the thyroid-related quality of life instrument ThyPRO exhibited differential item functioning

    DEFF Research Database (Denmark)

    Watt, Torquil; Grønvold, Mogens; Hegedüs, Laszlo

    2014-01-01

    To evaluate the extent of differential item functioning (DIF) within the thyroid-specific quality of life patient-reported outcome measure, ThyPRO, according to sex, age, education and thyroid diagnosis.......To evaluate the extent of differential item functioning (DIF) within the thyroid-specific quality of life patient-reported outcome measure, ThyPRO, according to sex, age, education and thyroid diagnosis....

  11. Modified economic order quantity (EOQ model for items with imperfect quality: Game-theoretical approaches

    Directory of Open Access Journals (Sweden)

    Milad Elyasi

    2014-04-01

    Full Text Available In the recent decade, studying the economic order quantity (EOQ models with imperfect quality has appealed to many researchers. Only few papers are published discussing EOQ models with imperfect items in a supply chain. In this paper, a two-echelon decentralized supply chain consisting of a manufacture and a supplier that both face just in time (JIT inventory problem is considered. It is sought to find the optimal number of the shipments and the quantity of each shipment in a way that minimizes the both manufacturer’s and the supplier’s cost functions. To the authors’ best knowledge, this is the first paper that deals with imperfect items in a decentralized supply chain. Thereby, three different game theoretical solution approaches consisting of two non-cooperative games and a cooperative game are proposed. Comparing the results of three different scenarios with those of the centralized model, the conclusions are drawn to obtain the best approach.

  12. Entry-Item-Quantity-ABC Analysis-Based Multitype Cigarette Fast Sorting System

    Directory of Open Access Journals (Sweden)

    Ying Zhao

    2012-01-01

    Full Text Available Numerous items, small order, and frequent delivery are the characteristics of many distribution centers. Such characteristics generally increase the operating costs of the distribution center. To remedy this problem, this study employs the Entry-Item-Quantity (EIQ method to identify the characteristic of the cigarette distribution center and further analyzes the importance degree of customers and the frequently ordered products by means of EQ/EN/IQ-B/IK statistic charts. Based on these analyses as well as the total replenishment cost optimization model, multipicking strategies and combined multitype picking equipment allocation is then formulated accordingly. With such design scheme, the cigarette picking costs of the distribution center are expected to reduce. Finally, the specific number of equipment is figured out in order to meet the capability demand of the case cigarette distribution center.

  13. Mixed-Format Test Score Equating: Effect of Item-Type Multidimensionality, Length and Composition of Common-Item Set, and Group Ability Difference

    Science.gov (United States)

    Wang, Wei

    2013-01-01

    Mixed-format tests containing both multiple-choice (MC) items and constructed-response (CR) items are now widely used in many testing programs. Mixed-format tests often are considered to be superior to tests containing only MC items although the use of multiple item formats leads to measurement challenges in the context of equating conducted under…

  14. A Case Study on an Item Writing Process: Use of Test Specifications, Nature of Group Dynamics, and Individual Item Writers' Characteristics

    Science.gov (United States)

    Kim, Jiyoung; Chi, Youngshin; Huensch, Amanda; Jun, Heesung; Li, Hongli; Roullion, Vanessa

    2010-01-01

    This article discusses a case study on an item writing process that reflects on our practical experience in an item development project. The purpose of the article is to share our lessons from the experience aiming to demystify item writing process. The study investigated three issues that naturally emerged during the project: how item writers use…

  15. Assessment of Differential Item Functioning in Health-Related Outcomes: A Simulation and Empirical Analysis with Hierarchical Polytomous Data

    Directory of Open Access Journals (Sweden)

    Zahra Sharafi

    2017-01-01

    Full Text Available Background. The purpose of this study was to evaluate the effectiveness of two methods of detecting differential item functioning (DIF in the presence of multilevel data and polytomously scored items. The assessment of DIF with multilevel data (e.g., patients nested within hospitals, hospitals nested within districts from large-scale assessment programs has received considerable attention but very few studies evaluated the effect of hierarchical structure of data on DIF detection for polytomously scored items. Methods. The ordinal logistic regression (OLR and hierarchical ordinal logistic regression (HOLR were utilized to assess DIF in simulated and real multilevel polytomous data. Six factors (DIF magnitude, grouping variable, intraclass correlation coefficient, number of clusters, number of participants per cluster, and item discrimination parameter with a fully crossed design were considered in the simulation study. Furthermore, data of Pediatric Quality of Life Inventory™ (PedsQL™ 4.0 collected from 576 healthy school children were analyzed. Results. Overall, results indicate that both methods performed equivalently in terms of controlling Type I error and detection power rates. Conclusions. The current study showed negligible difference between OLR and HOLR in detecting DIF with polytomously scored items in a hierarchical structure. Implications and considerations while analyzing real data were also discussed.

  16. Random number generation

    International Nuclear Information System (INIS)

    Coveyou, R.R.

    1974-01-01

    The subject of random number generation is currently controversial. Differing opinions on this subject seem to stem from implicit or explicit differences in philosophy; in particular, from differing ideas concerning the role of probability in the real world of physical processes, electronic computers, and Monte Carlo calculations. An attempt is made here to reconcile these views. The role of stochastic ideas in mathematical models is discussed. In illustration of these ideas, a mathematical model of the use of random number generators in Monte Carlo calculations is constructed. This model is used to set up criteria for the comparison and evaluation of random number generators. (U.S.)

  17. Algebraic number theory

    CERN Document Server

    Weiss, Edwin

    1998-01-01

    Careful organization and clear, detailed proofs characterize this methodical, self-contained exposition of basic results of classical algebraic number theory from a relatively modem point of view. This volume presents most of the number-theoretic prerequisites for a study of either class field theory (as formulated by Artin and Tate) or the contemporary treatment of analytical questions (as found, for example, in Tate's thesis).Although concerned exclusively with algebraic number fields, this treatment features axiomatic formulations with a considerable range of applications. Modem abstract te

  18. Advanced number theory

    CERN Document Server

    Cohn, Harvey

    1980-01-01

    ""A very stimulating book ... in a class by itself."" - American Mathematical MonthlyAdvanced students, mathematicians and number theorists will welcome this stimulating treatment of advanced number theory, which approaches the complex topic of algebraic number theory from a historical standpoint, taking pains to show the reader how concepts, definitions and theories have evolved during the last two centuries. Moreover, the book abounds with numerical examples and more concrete, specific theorems than are found in most contemporary treatments of the subject.The book is divided into three parts

  19. The emergence of number

    CERN Document Server

    Crossley, John N

    1987-01-01

    This book presents detailed studies of the development of three kinds of number. In the first part the development of the natural numbers from Stone-Age times right up to the present day is examined not only from the point of view of pure history but also taking into account archaeological, anthropological and linguistic evidence. The dramatic change caused by the introduction of logical theories of number in the 19th century is also treated and this part ends with a non-technical account of the very latest developments in the area of Gödel's theorem. The second part is concerned with the deve

  20. Professor Stewart's incredible numbers

    CERN Document Server

    Stewart, Ian

    2015-01-01

    Ian Stewart explores the astonishing properties of numbers from 1 to10 to zero and infinity, including one figure that, if you wrote it out, would span the universe. He looks at every kind of number you can think of - real, imaginary, rational, irrational, positive and negative - along with several you might have thought you couldn't think of. He explains the insights of the ancient mathematicians, shows how numbers have evolved through the ages, and reveals the way numerical theory enables everyday life. Under Professor Stewart's guidance you will discover the mathematics of codes,

  1. Fundamentals of number theory

    CERN Document Server

    LeVeque, William J

    1996-01-01

    This excellent textbook introduces the basics of number theory, incorporating the language of abstract algebra. A knowledge of such algebraic concepts as group, ring, field, and domain is not assumed, however; all terms are defined and examples are given - making the book self-contained in this respect.The author begins with an introductory chapter on number theory and its early history. Subsequent chapters deal with unique factorization and the GCD, quadratic residues, number-theoretic functions and the distribution of primes, sums of squares, quadratic equations and quadratic fields, diopha

  2. Numbers and computers

    CERN Document Server

    Kneusel, Ronald T

    2015-01-01

    This is a book about numbers and how those numbers are represented in and operated on by computers. It is crucial that developers understand this area because the numerical operations allowed by computers, and the limitations of those operations, especially in the area of floating point math, affect virtually everything people try to do with computers. This book aims to fill this gap by exploring, in sufficient but not overwhelming detail, just what it is that computers do with numbers. Divided into two parts, the first deals with standard representations of integers and floating point numb

  3. Elementary theory of numbers

    CERN Document Server

    Sierpinski, Waclaw

    1988-01-01

    Since the publication of the first edition of this work, considerable progress has been made in many of the questions examined. This edition has been updated and enlarged, and the bibliography has been revised.The variety of topics covered here includes divisibility, diophantine equations, prime numbers (especially Mersenne and Fermat primes), the basic arithmetic functions, congruences, the quadratic reciprocity law, expansion of real numbers into decimal fractions, decomposition of integers into sums of powers, some other problems of the additive theory of numbers and the theory of Gaussian

  4. On powerful numbers

    Directory of Open Access Journals (Sweden)

    R. A. Mollin

    1986-01-01

    Full Text Available A powerful number is a positive integer n satisfying the property that p2 divides n whenever the prime p divides n; i.e., in the canonical prime decomposition of n, no prime appears with exponent 1. In [1], S.W. Golomb introduced and studied such numbers. In particular, he asked whether (25,27 is the only pair of consecutive odd powerful numbers. This question was settled in [2] by W.A. Sentance who gave necessary and sufficient conditions for the existence of such pairs. The first result of this paper is to provide a generalization of Sentance's result by giving necessary and sufficient conditions for the existence of pairs of powerful numbers spaced evenly apart. This result leads us naturally to consider integers which are representable as a proper difference of two powerful numbers, i.e. n=p1−p2 where p1 and p2 are powerful numbers with g.c.d. (p1,p2=1. Golomb (op.cit. conjectured that 6 is not a proper difference of two powerful numbers, and that there are infinitely many numbers which cannot be represented as a proper difference of two powerful numbers. The antithesis of this conjecture was proved by W.L. McDaniel [3] who verified that every non-zero integer is in fact a proper difference of two powerful numbers in infinitely many ways. McDaniel's proof is essentially an existence proof. The second result of this paper is a simpler proof of McDaniel's result as well as an effective algorithm (in the proof for explicitly determining infinitely many such representations. However, in both our proof and McDaniel's proof one of the powerful numbers is almost always a perfect square (namely one is always a perfect square when n≢2(mod4. We provide in §2 a proof that all even integers are representable in infinitely many ways as a proper nonsquare difference; i.e., proper difference of two powerful numbers neither of which is a perfect square. This, in conjunction with the odd case in [4], shows that every integer is representable in

  5. Brief history of numbers

    CERN Document Server

    Corry, Leo

    2015-01-01

    The world around us is saturated with numbers. They are a fundamental pillar of our modern society, and accepted and used with hardly a second thought. But how did this state of affairs come to be? In this book, Leo Corry tells the story behind the idea of number from the early days of the Pythagoreans, up until the turn of the twentieth century. He presents an overview of how numbers were handled and conceived in classical Greek mathematics, in the mathematics of Islam, in European mathematics of the middle ages and the Renaissance, during the scientific revolution, all the way through to the

  6. Elementary number theory

    CERN Document Server

    Dudley, Underwood

    2008-01-01

    Ideal for a first course in number theory, this lively, engaging text requires only a familiarity with elementary algebra and the properties of real numbers. Author Underwood Dudley, who has written a series of popular mathematics books, maintains that the best way to learn mathematics is by solving problems. In keeping with this philosophy, the text includes nearly 1,000 exercises and problems-some computational and some classical, many original, and some with complete solutions. The opening chapters offer sound explanations of the basics of elementary number theory and develop the fundamenta

  7. The Effect of the Number of Syllables on Handwriting Production

    Science.gov (United States)

    Lambert, Eric; Kandel, Sonia; Fayol, Michel; Esperet, Eric

    2008-01-01

    Four experiments examined whether motor programming in handwriting production can be modulated by the syllable structure of the word to be written. This study manipulated the number of syllables. The items, words and pseudo-words, had 2, 3 or 4 syllables. French adults copied them three times. We measured the latencies between the visual…

  8. Interaction between numbers and size during visual search

    NARCIS (Netherlands)

    Krause, F.; Bekkering, H.; Pratt, J.; Lindemann, O.

    2017-01-01

    The current study investigates an interaction between numbers and physical size (i.e. size congruity) in visual search. In three experiments, participants had to detect a physically large (or small) target item among physically small (or large) distractors in a search task comprising single-digit

  9. Suspect/Counterfeit Items Information Guide for Subcontractors/Suppliers

    Energy Technology Data Exchange (ETDEWEB)

    Tessmar, Nancy D. [Los Alamos National Laboratory; Salazar, Michael J. [Los Alamos National Laboratory

    2012-09-18

    Counterfeiting of industrial and commercial grade items is an international problem that places worker safety, program objectives, expensive equipment, and security at risk. In order to prevent the introduction of Suspect/Counterfeit Items (S/CI), this information sheet is being made available as a guide to assist in the implementation of S/CI awareness and controls, in conjunction with subcontractor's/supplier's quality assurance programs. When it comes to counterfeit goods, including industrial materials, items, and equipment, no market is immune. Some manufactures have been known to misrepresent their products and intentionally use inferior materials and processes to manufacture substandard items, whose properties can significantly cart from established standards and specifications. These substandard items termed by the Department of Energy (DOE) as S/CI, pose immediate and potential threats to the safety of DOE and contractor workers, the public, and the environment. Failure of certain systems and processes caused by an S/CI could also have national security implications at Los Alamos National Laboratory (LANL). Nuclear Safety Rules (federal Laws), DOE Orders, and other regulations set forth requirements for DOE contractors to implement effective controls to assure that items and services meet specified requirements. This includes techniques to implement and thereby minimizing the potential threat of entry of S/CI to LANL. As a qualified supplier of goods or services to the LANL, your company will be required to establish and maintain effective controls to prevent the introduction of S/CI to LANL. This will require that your company warrant that all items (including their subassemblies, components, and parts) sold to LANL are genuine (i.e. not counterfeit), new, and unused, and conform to the requirements of the LANL purchase orders/contracts unless otherwise approved in writing to the Los Alamos National Security (LANS) contract administrator

  10. Rats Remember Items in Context Using Episodic Memory.

    Science.gov (United States)

    Panoz-Brown, Danielle; Corbin, Hannah E; Dalecki, Stefan J; Gentry, Meredith; Brotheridge, Sydney; Sluka, Christina M; Wu, Jie-En; Crystal, Jonathon D

    2016-10-24

    Vivid episodic memories in people have been characterized as the replay of unique events in sequential order [1-3]. Animal models of episodic memory have successfully documented episodic memory of a single event (e.g., [4-8]). However, a fundamental feature of episodic memory in people is that it involves multiple events, and notably, episodic memory impairments in human diseases are not limited to a single event. Critically, it is not known whether animals remember many unique events using episodic memory. Here, we show that rats remember many unique events and the contexts in which the events occurred using episodic memory. We used an olfactory memory assessment in which new (but not old) odors were rewarded using 32 items. Rats were presented with 16 odors in one context and the same odors in a second context. To attain high accuracy, the rats needed to remember item in context because each odor was rewarded as a new item in each context. The demands on item-in-context memory were varied by assessing memory with 2, 3, 5, or 15 unpredictable transitions between contexts, and item-in-context memory survived a 45 min retention interval challenge. When the memory of item in context was put in conflict with non-episodic familiarity cues, rats relied on item in context using episodic memory. Our findings suggest that rats remember multiple unique events and the contexts in which these events occurred using episodic memory and support the view that rats may be used to model fundamental aspects of human cognition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Volume 9 Number 1

    African Journals Online (AJOL)

    OLUWOLE

    Agro-Science Journal of Tropical Agriculture, Food, Environment and Extension. Volume 9 Number 1 ... of persistent dumping of cheap subsidized food imports from developed ... independence of the inefficiency effects in the two estimation ...

  12. High Reynolds Number Turbulence

    National Research Council Canada - National Science Library

    Smits, Alexander J

    2007-01-01

    The objectives of the grant were to provide a systematic study to fill the gap between existing research on low Reynolds number turbulent flows to the kinds of turbulent flows encountered on full-scale vehicles...

  13. Crunching the Numbers

    International Development Research Centre (IDRC) Digital Library (Canada)

    Operating a Demographic Surveillance System (DSS) like this one requires a blend of high-tech number-crunching ability and .... views follow a standardized format that takes several ... general levels of health and to the use of health services.

  14. Quantum random number generator

    Science.gov (United States)

    Pooser, Raphael C.

    2016-05-10

    A quantum random number generator (QRNG) and a photon generator for a QRNG are provided. The photon generator may be operated in a spontaneous mode below a lasing threshold to emit photons. Photons emitted from the photon generator may have at least one random characteristic, which may be monitored by the QRNG to generate a random number. In one embodiment, the photon generator may include a photon emitter and an amplifier coupled to the photon emitter. The amplifier may enable the photon generator to be used in the QRNG without introducing significant bias in the random number and may enable multiplexing of multiple random numbers. The amplifier may also desensitize the photon generator to fluctuations in power supplied thereto while operating in the spontaneous mode. In one embodiment, the photon emitter and amplifier may be a tapered diode amplifier.

  15. Solar Indices - Sunspot Numbers

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  16. Really big numbers

    CERN Document Server

    Schwartz, Richard Evan

    2014-01-01

    In the American Mathematical Society's first-ever book for kids (and kids at heart), mathematician and author Richard Evan Schwartz leads math lovers of all ages on an innovative and strikingly illustrated journey through the infinite number system. By means of engaging, imaginative visuals and endearing narration, Schwartz manages the monumental task of presenting the complex concept of Big Numbers in fresh and relatable ways. The book begins with small, easily observable numbers before building up to truly gigantic ones, like a nonillion, a tredecillion, a googol, and even ones too huge for names! Any person, regardless of age, can benefit from reading this book. Readers will find themselves returning to its pages for a very long time, perpetually learning from and growing with the narrative as their knowledge deepens. Really Big Numbers is a wonderful enrichment for any math education program and is enthusiastically recommended to every teacher, parent and grandparent, student, child, or other individual i...

  17. Development of a lack of appetite item bank for computer-adaptive testing (CAT)

    DEFF Research Database (Denmark)

    Thamsborg, Lise Laurberg Holst; Petersen, Morten Aa; Aaronson, Neil K

    2015-01-01

    to 12 lack of appetite items. CONCLUSIONS: Phases 1-3 resulted in 12 lack of appetite candidate items. Based on a field testing (phase 4), the psychometric characteristics of the items will be assessed and the final item bank will be generated. This CAT item bank is expected to provide precise...

  18. Remembered but unused: the accessory items in working memory that do not guide attention

    NARCIS (Netherlands)

    Peters, Judith C.; Goebel, Rainer; Roelfsema, Pieter R.

    2009-01-01

    If we search for an item, a representation of this item in our working memory guides attention to matching items in the visual scene. We can hold multiple items in working memory. Do all these items guide attention in parallel? We asked participants to detect a target object in a stream of objects

  19. Robust Scale Transformation Methods in IRT True Score Equating under Common-Item Nonequivalent Groups Design

    Science.gov (United States)

    He, Yong

    2013-01-01

    Common test items play an important role in equating multiple test forms under the common-item nonequivalent groups design. Inconsistent item parameter estimates among common items can lead to large bias in equated scores for IRT true score equating. Current methods extensively focus on detection and elimination of outlying common items, which…

  20. Using a Linear Regression Method to Detect Outliers in IRT Common Item Equating

    Science.gov (United States)

    He, Yong; Cui, Zhongmin; Fang, Yu; Chen, Hanwei

    2013-01-01

    Common test items play an important role in equating alternate test forms under the common item nonequivalent groups design. When the item response theory (IRT) method is applied in equating, inconsistent item parameter estimates among common items can lead to large bias in equated scores. It is prudent to evaluate inconsistency in parameter…

  1. The Congruent Number Problem

    Indian Academy of Sciences (India)

    One could endlessly churn out congruent numbers following the method in Box 1 without being certain when a given number n (or n x m 2, for some integer m) will ap- pear on the list. Continuing in this way ·would exhaust one's computing resources, not to mention one's patience! Also, this procedure is of no avail if n is not ...

  2. The Brothel Phone Number

    DEFF Research Database (Denmark)

    Korsby, Trine Mygind

    2017-01-01

    Taking a point of departure in negotiations for access to a phone number for a brothel abroad, the article demonstrates how a group of pimps in Eastern Romania attempt to extend their local business into the rest of the EU. The article shows how the phone number works as a micro-infrastructure in......Taking a point of departure in negotiations for access to a phone number for a brothel abroad, the article demonstrates how a group of pimps in Eastern Romania attempt to extend their local business into the rest of the EU. The article shows how the phone number works as a micro...... in turn cultivate and maximize uncertainty about themselves in others. When making the move to go abroad into unknown terrains, accessing the infrastructure generated by the phone number can provide certainty and consolidate one’s position within criminal networks abroad. However, at the same time......, mishandling the phone number can be dangerous and in that sense produce new doubts and uncertainties....

  3. LLWnotes - Volume 11, Number 4

    International Nuclear Information System (INIS)

    1996-05-01

    This document is the May 1996 issue of LLWnotes. It contains articles and news items on the following topics: news items related to states and compacts; Low-Level Radioactive Waste (LLW) Forum activities; court rulings and calendars; US DOE testing at Ward Valley; US BLM contract with Lawrence Livermore National Laboratory; Mixed Waste Pilot Project Schedule; extension of US EPA's mixed waste enforcement moratorium; EPA Advisory Committee on research program operation; and decommissioning

  4. LLWnotes - Volume 11, Number 4

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-01

    This document is the May 1996 issue of LLWnotes. It contains articles and news items on the following topics: news items related to states and compacts; Low-Level Radioactive Waste (LLW) Forum activities; court rulings and calendars; US DOE testing at Ward Valley; US BLM contract with Lawrence Livermore National Laboratory; Mixed Waste Pilot Project Schedule; extension of US EPA`s mixed waste enforcement moratorium; EPA Advisory Committee on research program operation; and decommissioning.

  5. Differential item functioning of the UWES-17 in South Africa

    Directory of Open Access Journals (Sweden)

    Leanne Goliath-Yarde

    2011-11-01

    Research purpose: This study assesses the Differential Item Functioning (DIF of the Utrecht Work Engagement Scale (UWES-17 for different South African cultural groups in a South African company. Motivation for the study: Organisations are using the UWES-17 more and more in South Africa to assess work engagement. Therefore, research evidence from psychologists or assessment practitioners on its DIF across different cultural groups is necessary. Research design, approach and method: The researchers conducted a Secondary Data Analysis (SDA on the UWES-17 sample (n = 2429 that they obtained from a cross-sectional survey undertaken in a South African Information and Communication Technology (ICT sector company (n = 24 134. Quantitative item data on the UWES-17 scale enabled the authors to address the research question. Main findings: The researchers found uniform and/or non-uniform DIF on five of the vigour items, four of the dedication items and two of the absorption items. This also showed possible Differential Test Functioning (DTF on the vigour and dedication dimensions. Practical/managerial implications: Based on the DIF, the researchers suggested that organisations should not use the UWES-17 comparatively for different cultural groups or employment decisions in South Africa. Contribution/value add: The study provides evidence on DIF and possible DTF for the UWES-17. However, it also raises questions about possible interaction effects that need further investigation.

  6. Optimal lot sizing in screening processes with returnable defective items

    Science.gov (United States)

    Vishkaei, Behzad Maleki; Niaki, S. T. A.; Farhangi, Milad; Rashti, Mehdi Ebrahimnezhad Moghadam

    2014-07-01

    This paper is an extension of Hsu and Hsu (Int J Ind Eng Comput 3(5):939-948, 2012) aiming to determine the optimal order quantity of product batches that contain defective items with percentage nonconforming following a known probability density function. The orders are subject to 100 % screening process at a rate higher than the demand rate. Shortage is backordered, and defective items in each ordering cycle are stored in a warehouse to be returned to the supplier when a new order is received. Although the retailer does not sell defective items at a lower price and only trades perfect items (to avoid loss), a higher holding cost incurs to store defective items. Using the renewal-reward theorem, the optimal order and shortage quantities are determined. Some numerical examples are solved at the end to clarify the applicability of the proposed model and to compare the new policy to an existing one. The results show that the new policy provides better expected profit per time.

  7. INTERDEPENDENCE OF COST AND QUALITY OF ITEMS OF REAL ESTATE

    Directory of Open Access Journals (Sweden)

    Lukmanova Inessa Galeevna

    2012-10-01

    Calculation of reduction of the overall cost of the real estate item that has improved quality indicators in comparison with the overall cost of the real estate item of satisfactory quality, taken as a benchmark, is made. The nature of interrelation between the quality of building works and maintenance expenses is provided. The overall cost of the item increases alongside with the increase of its quality, therefore the pre-set quality indicator should be defined by taking account of the market conditions, rates charged for building works and payable by buyers, and the amount of building works that sell at a higher price. The indicator of the overall cost of the item of real estate, if forthcoming operational expenses are taken into account, i.e. calculated for the course of the overall life cycle of the item, is essential if the investor is going to maintain the building. Investors often act as sellers of completed buildings; therefore, the product price set at the time when it is offered for sale is of particular importance.

  8. Persistent consequences of atypical early number concepts

    Directory of Open Access Journals (Sweden)

    Michèle M. M. Mazzocco

    2013-09-01

    Full Text Available How does symbolic number knowledge performance help identify young children at risk for poor mathematics achievement outcomes? In research and practice, classification of mathematics learning disability (MLD, or dyscalculia is typically based on composite scores from broad measures of mathematics achievement. These scores do predict later math achievement levels, but do not specify the nature of math difficulties likely to emerge among students at greatest risk for long-term mathematics failure. Here we report that gaps in 2nd and 3rd graders’ number knowledge predict specific types of errors made on math assessments at Grade 8. Specifically, we show that early whole number misconceptions predict slower and less accurate performance, and atypical computational errors, on Grade 8 arithmetic tests. We demonstrate that basic number misconceptions can be detected by idiosyncratic responses to number knowledge items, and that when such misconceptions are evident during primary school they persist throughout the school age years, with variable manifestation throughout development. We conclude that including specific qualitative assessments of symbolic number knowledge in primary school may provide greater specificity of the types of difficulties likely to emerge among students at risk for poor mathematics outcomes.

  9. Few items in the thyroid-related quality of life instrument ThyPRO exhibited differential item functioning.

    Science.gov (United States)

    Watt, Torquil; Groenvold, Mogens; Hegedüs, Laszlo; Bonnema, Steen Joop; Rasmussen, Åse Krogh; Feldt-Rasmussen, Ulla; Bjorner, Jakob Bue

    2014-02-01

    To evaluate the extent of differential item functioning (DIF) within the thyroid-specific quality of life patient-reported outcome measure, ThyPRO, according to sex, age, education and thyroid diagnosis. A total of 838 patients with benign thyroid diseases completed the ThyPRO questionnaire (84 five-point items, 13 scales). Uniform and nonuniform DIF were investigated using ordinal logistic regression, testing for both statistical significance and magnitude (∆R(2) > 0.02). Scale level was estimated by the sum score, after purification. Twenty instances of DIF in 17 of the 84 items were found. Eight according to diagnosis, where the goiter scale was the one most affected, possibly due to differing perceptions in patients with auto-immune thyroid diseases compared to patients with simple goiter. Eight DIFs according to age were found, of which 5 were in positively worded items, which younger patients were more likely to endorse; one according to gender: women were more likely to report crying, and three according to educational level. The vast majority of DIF had only minor influence on the scale scores (0.1-2.3 points on the 0-100 scales), but two DIF corresponded to a difference of 4.6 and 9.8, respectively. Ordinal logistic regression identified DIF in 17 of 84 items. The potential impact of this on the present scales was low, but items displaying DIF could be avoided when developing abbreviated scales, where the potential impact of DIF (due to fewer items) will be larger.

  10. ‘Forget me (not?’ – Remembering forget-items versus un-cued items in directed forgetting

    Directory of Open Access Journals (Sweden)

    Bastian eZwissler

    2015-11-01

    Full Text Available Humans need to be able to selectively control their memories. Here, we investigate the underlying processes in item-method directed forgetting and compare the classic active memory cues in this paradigm with a passive instruction. Typically, individual items are presented and each is followed by either a forget- or remember-instruction. On a surprise test of all items, memory is then worse for to-be-forgotten items (TBF compared to to-be-remembered items (TBR. This is thought to result from selective rehearsal of TBR, or from active inhibition of TBF, or from both. However, evidence suggests that if a forget instruction initiates active processing, paradoxical effects may also arise. To investigate the underlying mechanisms, four experiments were conducted where un-cued items (UI were introduced and recognition performance was compared between TBR, TBF and UI stimuli. Accuracy was encouraged via a performance-dependent monetary bonus. Across all experiments, including perceptually fully matched variants, memory accuracy for TBF was reduced compared to TBR, but better than for UI. Moreover, participants used a more conservative response criterion when responding to TBF stimuli. Thus, ironically, the F cue results in active processing, but this does not have inhibitory effects that would impair recognition memory beyond a un-cued baseline condition. This casts doubts on inhibitory accounts of item-method directed forgetting and is also difficult to reconcile with pure selective rehearsal of TBR. While the F-cue does induce active processing, this does not result in particularly successful forgetting. The pattern seems most consistent with the notion of ironic processing.

  11. Report number codes

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, R.N. (ed.)

    1985-05-01

    This publication lists all report number codes processed by the Office of Scientific and Technical Information. The report codes are substantially based on the American National Standards Institute, Standard Technical Report Number (STRN)-Format and Creation Z39.23-1983. The Standard Technical Report Number (STRN) provides one of the primary methods of identifying a specific technical report. The STRN consists of two parts: The report code and the sequential number. The report code identifies the issuing organization, a specific program, or a type of document. The sequential number, which is assigned in sequence by each report issuing entity, is not included in this publication. Part I of this compilation is alphabetized by report codes followed by issuing installations. Part II lists the issuing organization followed by the assigned report code(s). In both Parts I and II, the names of issuing organizations appear for the most part in the form used at the time the reports were issued. However, for some of the more prolific installations which have had name changes, all entries have been merged under the current name.

  12. Report number codes

    International Nuclear Information System (INIS)

    Nelson, R.N.

    1985-05-01

    This publication lists all report number codes processed by the Office of Scientific and Technical Information. The report codes are substantially based on the American National Standards Institute, Standard Technical Report Number (STRN)-Format and Creation Z39.23-1983. The Standard Technical Report Number (STRN) provides one of the primary methods of identifying a specific technical report. The STRN consists of two parts: The report code and the sequential number. The report code identifies the issuing organization, a specific program, or a type of document. The sequential number, which is assigned in sequence by each report issuing entity, is not included in this publication. Part I of this compilation is alphabetized by report codes followed by issuing installations. Part II lists the issuing organization followed by the assigned report code(s). In both Parts I and II, the names of issuing organizations appear for the most part in the form used at the time the reports were issued. However, for some of the more prolific installations which have had name changes, all entries have been merged under the current name

  13. Optimal Number of Questionnaire Response Categories

    Directory of Open Access Journals (Sweden)

    W. Paul Jones

    2013-05-01

    Full Text Available Two multi-instrument investigations in a university clinic/lab provided an opportunity to explore the impact of reducing the number of response alternatives in a scale measuring vocational personality traits. In a simulation study, a standard computer-based administration provided a numeric scale for each item ranging from 0 to 10. The tests were then rescored to simulate the effect of only three choices. For the follow-up study, two versions of the scale were created, one with two response options and the other with six response options, and were randomly assigned to participants. Typical relationships were evident between the vocational personality traits and scores on standard measures of core personality traits with negligible impact from reducing the number of response alternatives. Neither the ability of the participants nor the self-reported distress had a measurable impact on the utility of the results with the reduction in response alternatives.

  14. A Numbers Game

    DEFF Research Database (Denmark)

    Levin, Bruce R; McCall, Ingrid C.; Perrot, Veronique

    2017-01-01

    We postulate that the inhibition of growth and low rates of mortality of bacteria exposed to ribosome-binding antibiotics deemed bacteriostatic can be attributed almost uniquely to these drugs reducing the number of ribosomes contributing to protein synthesis, i.e., the number of effective......-targeting bacteriostatic antibiotics, the time before these bacteria start to grow again when the drugs are removed, referred to as the post-antibiotic effect (PAE), is markedly greater for constructs with fewer rrn operons than for those with more rrn operons. We interpret the results of these other experiments reported...... here as support for the hypothesis that the reduction in the effective number of ribosomes due to binding to these structures provides a sufficient explanation for the action of bacteriostatic antibiotics that target these structures....

  15. Quantum random number generator

    Science.gov (United States)

    Soubusta, Jan; Haderka, Ondrej; Hendrych, Martin

    2001-03-01

    Since reflection or transmission of a quantum particle on a beamsplitter is inherently random quantum process, a device built on this principle does not suffer from drawbacks of neither pseudo-random computer generators or classical noise sources. Nevertheless, a number of physical conditions necessary for high quality random numbers generation must be satisfied. Luckily, in quantum optics realization they can be well controlled. We present an easy random number generator based on the division of weak light pulses on a beamsplitter. The randomness of the generated bit stream is supported by passing the data through series of 15 statistical test. The device generates at a rate of 109.7 kbit/s.

  16. The LHC in numbers

    CERN Multimedia

    Alizée Dauvergne

    2010-01-01

    What makes the LHC the biggest particle accelerator in the world? Here are some of the numbers that characterise the LHC, and their equivalents in terms that are easier for us to imagine.   Feature Number Equivalent Circumference ~ 27 km   Distance covered by beam in 10 hours ~ 10 billion km a round trip to Neptune Number of times a single proton travels around the ring each second 11 245   Speed of protons first entering the LHC 299 732 500 m/s 99.9998 % of the speed of light Speed of protons when they collide 299 789 760 m/s 99.9999991 % of the speed of light Collision temperature ~ 1016 °C ove...

  17. Safety classification of items in Tianwan Nuclear Power Plant

    International Nuclear Information System (INIS)

    Sun Yongbin

    2005-01-01

    The principle of integrality, moderation and equilibrium should be considered in the safety classification of items in nuclear power plant. The basic ways for safety classification of items is to classify the safety function based on the effect of the outside enclosure damage of the items (parts) on the safety. Tianwan Nuclear Power Plant adopts Russian VVER-1000/428 type reactor, it safety classification mainly refers to Russian Guidelines and standards. The safety classification of the electric equipment refers to IEEE-308(80) standard, including 1E and Non 1E classification. The safety classification of the instrumentation and control equipment refers to GB/T 15474-1995 standard, including safety 1E, safety-related SR and NC non-safety classification. The safety classification of Tianwan Nuclear Power Plant has to be approved by NNSA and satisfy Chinese Nuclear Safety Guidelines. (authors)

  18. Assessing Differential Item Functioning on the Test of Relational Reasoning

    Directory of Open Access Journals (Sweden)

    Denis Dumas

    2018-03-01

    Full Text Available The test of relational reasoning (TORR is designed to assess the ability to identify complex patterns within visuospatial stimuli. The TORR is designed for use in school and university settings, and therefore, its measurement invariance across diverse groups is critical. In this investigation, a large sample, representative of a major university on key demographic variables, was collected, and the resulting data were analyzed using a multi-group, multidimensional item-response theory model-comparison procedure. No significant differential item functioning was found on any of the TORR items across any of the demographic groups of interest. This finding is interpreted as evidence of the cultural fairness of the TORR, and potential test-development choices that may have contributed to that cultural fairness are discussed.

  19. Directed forgetting of complex pictures in an item method paradigm.

    Science.gov (United States)

    Hauswald, Anne; Kissler, Johanna

    2008-11-01

    An item-cued directed forgetting paradigm was used to investigate the ability to control episodic memory and selectively encode complex coloured pictures. A series of photographs was presented to 21 participants who were instructed to either remember or forget each picture after it was presented. Memory performance was later tested with a recognition task where all presented items had to be retrieved, regardless of the initial instructions. A directed forgetting effect--that is, better recognition of "to-be-remembered" than of "to-be-forgotten" pictures--was observed, although its size was smaller than previously reported for words or line drawings. The magnitude of the directed forgetting effect correlated negatively with participants' depression and dissociation scores. The results indicate that, at least in an item method, directed forgetting occurs for complex pictures as well as words and simple line drawings. Furthermore, people with higher levels of dissociative or depressive symptoms exhibit altered memory encoding patterns.

  20. Matrix Sampling of Items in Large-Scale Assessments

    Directory of Open Access Journals (Sweden)

    Ruth A. Childs

    2003-07-01

    Full Text Available Matrix sampling of items -' that is, division of a set of items into different versions of a test form..-' is used by several large-scale testing programs. Like other test designs, matrixed designs have..both advantages and disadvantages. For example, testing time per student is less than if each..student received all the items, but the comparability of student scores may decrease. Also,..curriculum coverage is maintained, but reporting of scores becomes more complex. In this paper,..matrixed designs are compared with more traditional designs in nine categories of costs:..development costs, materials costs, administration costs, educational costs, scoring costs,..reliability costs, comparability costs, validity costs, and reporting costs. In choosing among test..designs, a testing program should examine the costs in light of its mandate(s, the content of the..tests, and the financial resources available, among other considerations.