Probing interactions in multiple linear regression, latent curve analysis, and hierarchical linear modeling: Interactive calculation tools for establishing simple intercepts, simple slopes, and regions of significance
Kristopher J. Preacher (Vanderbilt University)
Patrick J. Curran (University of North Carolina at Chapel Hill)
Daniel J. Bauer (University of North Carolina at Chapel Hill)
The paper describing this web utility may be cited in APA style in the following manner:
Preacher, K. J., Curran, P. J., & Bauer, D. J. (2006). Computational tools for probing interaction effects in multiple linear regression, multilevel modeling, and latent curve analysis. Journal of Educational and Behavioral Statistics, 31, 437-448.
These web pages provide tools for probing significant 2-way or 3-way interaction effects in multiple linear regression (MLR), latent curve analysis (LCA), and hierarchical linear modeling (HLM). It is necessary first to obtain output from an appropriately conducted analysis investigating an interaction effect using other software. General discussions on how to conduct these analyses can be found in the references listed at the bottom of each page.
The primer on interaction effects in multiple linear regression contains a review of key concepts related to interaction effects in MLR.
Software With Similar Capabilities
These web calculators are intended for use in conjunction with any regression / multilevel / growth curve modeling software that provides analysis results and asymptotic (co)variances for interaction (moderation) models. Other software may be more convenient for some users. For example:
Original version posted May, 2006. Our thanks to the Carolina Structural Equation Modeling group (CSEM) for testing these pages.