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Understanding and Using Mediators and Moderators

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Abstract

Mediation and moderation are two theories for refining and understanding a causal relationship. Empirical investigation of mediators and moderators requires an integrated research design rather than the data analyses driven approach often seen in the literature. This paper described the conceptual foundation, research design, data analysis, as well as inferences involved in a mediation and/or moderation investigation in both experimental and non-experimental (i.e., correlational) contexts. The essential distinctions between the investigation of mediators and moderators were summarized and juxtaposed in an example of a causal relationship between test difficulty and test anxiety. In addition, the more elaborate models, moderated mediation and mediated moderation, the use of structural equation models, and the problems with model misspecification were discussed conceptually.

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Notes

  1. Path analysis and factor analysis are special cases of SEM. A path analysis is a type of SEM in which each variable has only one indicator and the relationship among the variables are specified. Hence, a path analysis approach to mediation and moderation does not deal with the problem of measurement errors, however, it, can deal with multiple univariate regression analyses in one model. A factor analysis is a type of SEM in which each latent variable has multiple indicators hence deals with the measurement error problem, but there are no relationship specified among the latent variables. A full SEM incorporates and integrates path analysis and factor analysis; the latent variables have multiple indicators and their relationships are modeled.

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  1. Department of ECPS, University of British Columbia, Scarfe Building, 2125 Main Mall, Vancouver, BC, Canada, V6T 1Z4

    Amery D. Wu & Bruno D. Zumbo

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Wu, A.D., Zumbo, B.D. Understanding and Using Mediators and Moderators. Soc Indic Res 87, 367–392 (2008). https://doi.org/10.1007/s11205-007-9143-1

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