Considering Comparability and Change over Time: Measurement Invariance as an Essential Consideration in Theory Development and Testing

Abstract

There is currently a great deal of attention in psychometric and statistical methods on ensuring measurement invariance when examining measures across time or populations. When measurement invariance is established, changes in scores over time or across groups can be attributed to changes in the construct rather than changes in reaction to or interpretation of the measurement instrument. When measurement in not invariant, it is possible that measured differences are due to the measurement instrument itself and not to the underlying phenomenon of interest. This chapter discusses the importance of establishing measurement invariance specifically in postsecondary settings, where it is anticipated that individuals' perspectives will change over time as a function of their higher education experiences. Using examples from several measures commonly used in higher education research, the concepts and processes underlying tests of measurement invariance are explained and analyses are interpreted using data from a US-based longitudinal study on bioscience PhD students. These measures include sense of belonging over time and across groups, mental well-being over time, and perceived mentorship quality over time. The chapter ends with a discussion about the implications of longitudinal and group measurement invariance as an important conceptual property for moving forward equitable, reproducible, and generalizable quantitative research in higher education. Invariance methods may further be relevant for addressing criticisms about quantitative analyses being biased toward majority populations that have been discussed by critical theorists engaging quantitative research strategies.

Citation

Litson, K. and Feldon, D. (2021), "Considering Comparability and Change over Time: Measurement Invariance as an Essential Consideration in Theory Development and Testing", Huisman, J. and Tight, M. (Ed.) Theory and Method in Higher Education Research (Theory and Method in Higher Education Research, Vol. 7), Emerald Publishing Limited, Leeds, pp. 93-111. https://doi.org/10.1108/S2056-375220210000007006