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Reference.org
Moderation (statistics)
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<p>In <a href="/facts/Statistics/DNPsKGYU">statistics</a> and <a href="/facts/Regression_analysis/n6z5Tf7K">regression analysis</a>, moderation (also known as effect modification) occurs when the relationship between two variables depends on a third variable. The third variable is referred to as the moderator variable (or effect modifier) or simply the moderator (or modifier). The effect of a moderating variable is characterized statistically as an <a href="/facts/Interaction_(statistics)/Kp0Cab6w">interaction</a>; that is, a <a href="/facts/Categorical_variable/3UQNkLqs">categorical</a> (e.g., sex, ethnicity, class) or <a href="/facts/Level_of_measurement/8GAxPxFv">continuous</a> (e.g., age, level of reward) <a href="/facts/Variable_(mathematics)/VbQlrvKz">variable</a> that is associated with the direction and/or magnitude of the relation between <a href="/facts/Dependent_and_independent_variables/dINfzIF2">dependent and independent variables</a>. Specifically within a <a href="/facts/Correlation/egkluAEm">correlational</a> analysis framework, a moderator is a third variable that affects the zero-order correlation between two other variables, or the value of the slope of the dependent variable on the independent variable. In <a href="/facts/Analysis_of_variance/HHR2jkDk">analysis of variance</a> (ANOVA) terms, a basic moderator effect can be represented as an <a href="/facts/Interaction_(statistics)/Kp0Cab6w">interaction</a> between a focal <a href="/facts/Statistical_independence/NUzQtnUL">independent</a> variable and a factor that specifies the appropriate conditions for its operation. </p>