A moderator variable
is, in general terms, a qualitative
(e.g., sex, race, class) or quantitative
(e.g., level of reward) variable
that affects the direction and/or strength of the relation between dependent and independent variables
. Specifically within a correlational
analysis framework, a moderator is a third variable that affects the zero-order correlation between two other variables. In analysis of variance
(ANOVA) terms, a basic moderator effect can be represented as an interaction
between a focal independent
variable and a factor that specifies the appropriate conditions for its operation (Baron and Kenny, 1986: p. 1174).
- Baron, R. M., & Kenny, D. A. (1986). "The moderator-mediator variable distinction in social psychological research: Conceptual, strategic, and statistical considerations." Journal of Personality and Social Psychology, Vol. 51, No. 6, pp. 1173-1182.