A fundamental premise in assessment is that the underlying construct is equivalent across different groups of students and that this structure does not vary over years. The pandemic has potentially impacted opportunity to learn and disrupted the internal structure of assessments in various ways. Past research has suggested that students tended to…

This article provides a brief introduction to the Rasch model. Motivation for using Rasch analyses is provided. Important Rasch model concepts and key aspects of result interpretation are introduced, with major points reinforced using a simulation demonstration. Concrete guidelines are provided regarding sample size and the evaluation of items.

This research is concerned with two topics in assessing model fit for categorical data analysis. The first topic involves the application of a limited-information overall test, introduced in the item response theory literature, to Structural Equation Modeling (SEM) of categorical outcome variables. Most popular SEM test statistics assess how well…

A psychological measurement model provides an explicit definition of (a) the theoretical and (b) the numerical relationships between observed scores and the latent variables that underlie the observed scores. Examination of the metric invariance of a measurement model involves testing the hypothesis that all components of the model relating…

Two indices for measuring the degree of conformity or consistency of an individual examinee's response pattern on a set of items are developed. The use of the indices for spotting aberrant response patterns of examinees is detailed. (Author/JKS)

The Rasch model for test analysis is described and compared with two-parameter and three-parameter latent-trait models. Conditional maximum likelihood equations for estimating item parameters are derived, and estimates of person parameters are described together with their confidence intervals. Goodness of fit tests are discussed, including a…