In this digital ITEMS module, we introduce 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. We walk through the key distinction between parametric and nonparametric models, introduce the…

Mokken scale analysis (MSA) is a probabilistic-nonparametric approach to item response theory (IRT) that can be used to evaluate fundamental measurement properties with less strict assumptions than parametric IRT models. This instructional module provides an introduction to MSA as a probabilistic-nonparametric framework in which to explore…

"Scaling" is the process of constructing a score scale that associates numbers or other ordered indicators with the performance of examinees. Scaling typically is conducted to aid users in interpreting test results. This module describes different types of raw scores and scale scores, illustrates how to incorporate various sources of…

This article discusses the range of validation studies conducted in Kansas in examining the validity of the National Teachers' Examination as a certification test for that state. It is argued that the validation of certification tests calls for a wider range of studies than typically are undertaken. (JAZ)

The author describes the evolution of the Scholastic Aptitude Test (SAT). He describes some of the contributions to educational research made by inquiries based on the SAT and gives particular attention to the way scaling and equating procedures for the SAT have evolved over the last half century. (Author/JAZ)