The Many Perspectives of Test Dimensionality: A Collaborative Narrative

• In Event: 25.082 - Fairmont Royal York Roundtable Session Three
  In Roundtable Session: 25.082-5 - Dimensionality and Estimation: Advancements and Applications in (Multidimensional) Item Response Theory and Factor Analysis

Abstract

In educational measurement, the term “dimensionality” has become highly ambiguous. From a test developer’s perspective, dimensionality may refer to characteristics of the test such as content or cognitive areas. From a psychometrician’s perspective, dimensionality may refer to a clustering of items via statistical analyses. Due to the variety of dimensionality definitions, it can become cumbersome to develop a coherent conversation comparing dimensionality across assessments. This study aims to investigate the dimensionality of multiple forms of a math test from two distinct approaches: 1. A confirmatory approach in which test specifications direct statistical analyses, and 2. An exploratory approach in which substantive dimension meaning is derived post-hoc. Finally, aggregate results are summarized and succinctly reported, reflecting both dimensionality perspectives.

Authors

• Alexandra Lay, University of North Carolina - Greensboro

• Terry A. Ackerman, University of Iowa