Article

Assessing the Measurement Equivalence of a Set of Items: Item-specific Diagnostics on an Interpretable Metric

Authors: Johan Braeken , Saskia van Laar (Maastricht University)

Abstract

The characteristic of `measuring the same thing repeatedly in the same way' makes psychological tests with equivalent items an attractive choice for one-off assessments and progress monitoring. A hierarchy of factor analysis measurement models formalizes the global equivalence of the item set. The traditional model comparison approach provides a binary statistical significance decision about the global level of equivalence, but interpretable local diagnostics to assess the degree of equivalence for specific items on a meaningful metric are not yet available. We introduce such item-specific effect-size diagnostics through smart use of the effect-coding identification rule to set the to-be-measured latent variable’s scale.

Keywords: factor analysis, measurement equivalence, effect size, congeneric, parallel

How to Cite: Braeken, J. & van Laar, S. (2026) “Assessing the Measurement Equivalence of a Set of Items: Item-specific Diagnostics on an Interpretable Metric”, Practical Assessment, Research, and Evaluation. 31(1). doi: https://doi.org/10.7275/pare.3048