Modeling (in)congruence in groups: A how-to guide for applying polynomial regression and response surface method to multilevel data.

Abstract

Objective: Group scholars often question whether the fit between group members and their respective teams or leaders is associated with an outcome variable. For example, do team members perceive the same team climate as their peers, and how does this affect subsequent outcomes? Such (in)congruence hypothesis-based research questions have been commonly investigated through the application of difference scores. However, ignoring the multidimensional relationship between two predictors and an outcome leads to severe misinterpretations. Therefore, our objective is to outline a relatively new method to test (in)congruence in groups. Method: Polynomial regression (PR) and response surface methodology (RSM) in combination can be used to test the (in)congruence hypothesis in psychological phenomena and provide explanatory power. This article outlines an introduction to the method and offers a how-to guide with an illustrated example of innovation teams. Results: The illustrative example showcases how multilevel PR and RSM can be used to analyze, report, and interpret data of (in)congruence hypothesis in group research. Conclusions: Two interpretation approaches are discussed, and common problems are considered when interpreting results. Some future directions for testing a(n) (in)congruence hypothesis with nested data are highlighted. R syntax is provided in the .

Introduction to special issue: Data analytic methods in group psychology and group psychotherapy.

“…As an overview, Berg et al (2023) outline polynomial regression (PR) and response surface methodology (RSM) as methods for testing (in)congruence hypothesis-based research questions in group research. The authors outline how PR and RSM in combination can be used to test the (in)congruence hypothesis in psychological phenomena while addressing the multidimensional relationship between two predictors and a criterion variable.…”