Statistical tests for moderator variables: Flaws in analyses recently proposed.

A procedure offered by Morris, Sherman, and Mansfield (1986) for testing hypotheses about interactions ("moderator variables") is unacceptable. A related proposal by Bobko (1986) is also problematic. One can appropriately test such hypotheses by stepwise regression, comparing an equation in the simple predictors with an equation that also includes the product of their deviation scores. There is, however, reason to believe that methods with greater statistical power can be found. (PsycINFO Database Record (c) 2010 APA, all rights reserved)