Relative importance analysis for the study of the family: Accepting the challenge of correlated predictors

Family researchers are often interested in the importance of variables to be included in the prediction of some outcome and have traditionally used multiple regression analysis (MR) to study variable importance. However, given the non-independence of family data, multicollinearity can be a pervasive phenomenon in this field of research and MR may produce poor or confusing results in the case of highly correlated predictors. In this article, I present two alternative techniques of analysis — relative weight analysis (RWA; Johnson, 2000) and dominance analysis (DA; Budescu, 1993) — both of which address questions pertaining to predictor comparisons and are able to provide a plausible assessment of importance among multiple correlated predictors. Examples of application of RWA and DA to address specific questions about family relationships are discussed.