Much research has been devoted to identification of differential item functioning (DIF), which occurs when the item responses for individuals from two groups differ after they are conditioned on the latent trait being measured by the scale. There has been less work examining differential step functioning (DSF), which is present for polytomous…

This article presents the performance of item response theory (IRT) models when double ratings are used as item scores over single ratings when rater effects are present. Study 1 examined the influence of the number of ratings on the accuracy of proficiency estimation in the generalized partial credit model (GPCM). Study 2 compared the accuracy of…

The usefulness of item response theory (IRT) models depends, in large part, on the accuracy of item and person parameter estimates. For the standard 3 parameter logistic model, for example, these parameters include the item parameters of difficulty, discrimination, and pseudo-chance, as well as the person ability parameter. Several factors impact…

This study compares five cognitive diagnostic models in search of optimal one(s) for English as a Second Language grammar test data. Using a unified modeling framework that can represent specific models with proper constraints, the article first fit the full model (the log-linear cognitive diagnostic model, LCDM) and investigated which model…

Drawing inferences about the extent to which student performance reflects instructional opportunities relies on the premise that the measure of student performance is reflective of instructional opportunities. An instructional sensitivity framework suggests that some assessments are more sensitive to detecting differences in instructional…

Using a sample of schools testing annually in grades 9-11 with a vertically linked series of assessments, a latent growth curve model is used to model test scores with student intercepts and slopes nested within school. Missed assessments can occur because of student mobility, student dropout, absenteeism, and other reasons. Missing data…

Testlets, or groups of related items, are commonly included in educational assessments due to their many logistical and conceptual advantages. Despite their advantages, testlets introduce complications into the theory and practice of educational measurement. Responses to items within a testlet tend to be correlated even after controlling for…

This study compared vertical scaling results for the Rasch model from BILOG-MG and WINSTEPS. The item and ability parameters for the simulated vocabulary tests were scaled across 11 grades; kindergarten through 10th. Data were based on real data and were simulated under normal and skewed distribution assumptions. WINSTEPS and BILOG-MG were each…

A sequential decision-making approach based on college grade point averages and test scores for teacher licensure decisions within the conjunctive model is contrasted with the compensatory model for decision making. Criteria for choosing one model over another and a rationale for favoring the conjunctive model are provided. (TJH)

The feasibility of combining criterion-referenced and norm-referenced tests into a school achievement test score to be used for school effectiveness classification was studied with 361 elementary schools across 2 years and across a subsample of 264 schools. Results support combining scores of different tests to measure school effectiveness. (SLD)

This article provides a framework for the rest of the articles in this special issue comparing the utility of three standard-setting methods with complex performance assessments. The context of the standard setting study is described, and the methods are outlined. (SLD)