Interaction Effect

An interaction effect is the simultaneous effect of two or more independent variables on at least one dependent variable in which their joint effect is significantly greater (or significantly less) than the sum of the parts. The presence of interaction effects in any kind of survey research is important because it tells researchers how two or more independent variables work together to impact the dependent variable. Including an interaction term effect in an analytic model provides the researcher with a better representation and understanding of the relationship between the dependent and independent variables. Further, it helps explain more of the variability in the dependent variable. An omitted interaction effect from a model where a nonnegligible interaction does in fact exist may result in a misrepresentation ...