This tutorial was written as an introduction to the basics of item response theory (IRT) modeling and its applications to health outcomes measurement for the National Cancer Institute’s Cancer Outcomes Measurement Working Group (COMWG). In no way this tutorial is meant to replace any text on measurement theory, but only serve as a stepping-stone for health care researchers to learn this methodo...

Item Response Theory (IRT) is a class of measurement models that offers a variety of methods, not only to measure latent properties, but also to assess and improve the quality of such measurement. The attractive properties of IRT models, however, can only be derived when the rather restrictive assumptions of the model hold for the data being considered. Lenient researchers will argue that the m...

The present study examined the psychometric properties of the Arabic version of Children's Self-report Social Skills Scale (CS) using a generalized partial credit model (GPCM). Data from 722 primary school children (401 boys and 321 girls) responses, in Egypt, were analyzed using GPCM. The results indicated that the 21 items are able to discriminate among the levels of children's social skills....

A test designed with built-in modifications and covering the same grade-level mathematics content provided more precise measurement of mathematics achievement for lower performing students with disabilities. Fourth-grade students with disabilities took a test based on modified state curricular standards for their mandated statewide mathematics assessment. To link the modified test with the gene...

The Bayley Short Form – Research Edition (BSF-R). At the base year (henceforth called the 9-month wave, as children were approximately 9 months of age at the time of assessment) and first follow-up (henceforth called the 2-year wave, since children were approximately 2 years of age at the time of assessment), the Bayley Short Form-Research Edition (BSF-R) was used. The BSF-R consists of a subse...

During the 2004–2005 school year, over 900 eighthgrade students used an online intelligent tutoring system, the Assistment System of He ernan, et al. (2001), to prepare for the mathematics portion of the Massachusetts Comprehensive Assessment System (MCAS) end-of-year exam. A transfer model, identifying the skills that each tutoring task and exam problem depends upon, was developed to help alig...

The aim of this work was to assess psychology students’ attitudes toward statistics trough credit partial model of IRT, and to identify the association among the students’ attitudes, academic performance, and selfperception in Statistics. A not random sample of 361 Psychology students answered the identification questionnaire and the attitudes scale towards Statistics. The students aged 18-65, ...

This research examined students’ responses to mathematics problem-solving tasks and applied a general multidimensional IRT model at the response category level. In doing so, cognitive processes were identified and modelled through item response modelling to extract more information than would be provided using conventional practices in scoring items. More specifically, the study consisted of tw...