The article provides an overview of goodness of fit assessment methods for item response theory (IRT) models. It is now possible to obtain accurate p-values of the overall fit of the model if bivariate information statistics are used. Several alternative approaches are described. As the validity of inferences drawn on the fitted model depends on the magnitude of the misfit, if the model is reje...

The deliverable gives a focus on how to transport different formats of ViSiCAST data via the broadcast channels. Furthermore the deliverable will describe different implementations of the Multimedia Home Platform MHP and the implications for ViSiCAST. Some results gained in subjective tests are given in a thesis related to workpackage 1. At the end of the deliverable some impressions of the boo...

The research described in this paper deals solely with the effect of the position of an item within a test on examinee's responding behavior at the item level. For simplicity's sake, this effect will be referred to as practice effect when the result is improved examinee performance and as fatigue effect when the result is poorer examinee performance. Item response theory item statistics were us...

Interest in end-of-year accountability exams has increased dramatically since the passing of the NCLB law in 2001. This push has impacted educational research in a wide variety of ways, including a strong desire to be able to model student work in order to make conclusive statements about what students know and how this relates to how they will perform on end-of-year standardized exams. This th...

Item response theory (IRT) is an important method of assessing the validity of measurement scales that is underutilized in the field of psychiatry. IRT describes the relationship between a latent trait (e.g., the construct that the scale proposes to assess), the properties of the items in the scale, and respondents' answers to the individual items. This paper introduces the basic premise, assum...

Various survey instruments have been used to measure patient safety culture. Many of these instruments use a (usually5-point) Likert scale. This studyused the Safety Attitudes Questionnaire-Korean version (SAQ-K), consisting of 34 items in six domains, to examine whether other scales, such as dichotomized and trichotomized scales, present equivalent estimates to the currently used 5-point Liker...

This study assessed the potential influence of social desirability (SD) response bias on the E, N, and P EPQ-R scores at the level of individual items. The study was based on a bidimensional IRT model which was fitted in a large sample. This allowed a detailed analysis of both the internal validities of the items and the content of the items which were most affected by SD. The E items were leas...

R ecent years have witnessed greatly increased appreciation of the centrality of good teach ing to the effectiveness of schooling and of the role of research on teaching in developing a knowledge base to inform the teaching profession. This article draws on findings from the past decade of research on teaching, and in particular on findings developed at the Institute for Research on Teaching (I...

In multidimensional forced-choice (MFC) questionnaires, items measuring different attributes are presented in blocks, and participants have to rank order the items within each block (fully or partially). Such comparative formats can reduce the impact of numerous response biases often affecting single-stimulus items (aka rating or Likert scales). However, if scored with traditional methodology, ...

Researchers commonly apply item response theory (IRT) models to binary and ordinal items in order to measure an underlying trait using a collection of observed responses to test questions or items. For binary items, a common IRT model is the two parameter logistic (2PL) form. Assume that we have observed p item responses for n individuals where a correct responses is designated with a ’1’ and a...