Testing the Tests: Investigating Measurement Invariance in Assessments of Cognitive and Language Abilities

Abstract

This paper discusses the measurement invariance of assessment instruments. The purpose of measurement invariance testing is to assess the extent to which a measured construct has comparable meaning across different groups or measurement points, to ensure that comparisons of these groups or measures to each other are appropriate. The paper provides an overview of recent and classic papers discussing conceptual and methodological aspects of invariance testing. Specific focus is placed on the available data on invariance testing for the assessments of cognitive and language abilities, and on the significance of invariance for the accurate assessment of individual and between-group differences. Finally, current approaches to invariance testing within structural equation modelling and item response theory are discussed. This paper may serve as an introduction to the concept of measurement invariance. It will be useful to readers interested in improving the quality of measurement instruments and making more reliable inferences about psychological phenomena.