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Item Response Theory

Digital Module 03: Nonparametric Item Response Theory
In this digital ITEMS module Dr. Stefanie Wind introduces the framework of nonparametric item response theory (IRT), in particular Mokken scaling, which can be used to evaluate fundamental measurement properties with less strict assumptions than parametric IRT models.
Digital Module 06: Posterior Predictive Model Checking
​In this digital ITEMS module, Dr. Allison Ames and Aaron Myers ​discuss the most common Bayesian approach to model-data fit evaluation, which is called Posterior Predictive Model Checking (PPMC), for simple linear regression and item response theory models.
Digital Module 08: Foundations of Operational Item Analysis
In this digital ITEMS module, Dr. Hanwook Yoo and Dr. Ronald K. Hambleton provide an accessible overview of operational item analysis approaches for dichotomously scored items within the frameworks of classical test theory and item response theory.
Module 07: Comparison of 1-, 2-, and 3-Parameter IRT Models
​This ITEM module discusses the 1-, 2-, and 3-parameter logistic item response theory models.
Module 16: Comparison of Classical Test Theory and Item Response Theory
This ITEM module provides a nontechnical comparison of classical test theory and item response theory.
Module 21: Multidimensional Item Response Theory
This ITEM module illustrates how test practitioners and researchers can apply multidimensional item response theory (MIRT) to understand better what their tests are measuring, how accurately the different composites of ability are being assessed, and how this information can be cycled back into the test development process.
Module 35: Polytomous Item Response Theory Models
This ITEMS module provides an accessible overview of polytomous IRT models.
Module 39: Polytomous Item Response Theory Models: Problems with the Step Metaphor
The Problem With the Step Metaphor for Polytomous Models for Ordinal Assessments
Module 40: Item Fit Statistics for Item Response Theory Models
This ITEM module provides an overview of methods used for evaluating the fit of IRT models.
Module 45: Mokken-scale Analysis
This instructional module provides an introduction to MSA as a probabilistic-nonparametric framework in which to explore measurement quality, with an emphasis on its application in the context of educational assessment.