18.2 Key Terminology

• Main Effect: The effect of an independent variable without considering interactions.
• Interaction Effect: The combined effect of \(X\) and \(M\) on \(Y\).
• Simple Slope: The slope of \(X\) on \(Y\) at a specific value of \(M\) (used when \(M\) is continuous).
• Simple Effect: The effect of \(X\) on \(Y\) at a particular level of \(M\) when \(X\) is categorical.