Medium
Hierarchical Regression
Free
A health researcher predicts systolic blood pressure (Y). Step 1 includes age and BMI. Step 2 adds weekly exercise minutes. Step 3 adds the interaction term BMI × exercise (after mean-centering BMI and exercise). Which result would provide the strongest evidence of moderation (i.e., exercise moderates the effect of BMI on blood pressure)?
A
In Step 3, the BMI × exercise coefficient is significant (p < .05) and R² Change from Step 2 to Step 3 is significant.
B
In Step 2, exercise has a significant coefficient (p < .05), regardless of the interaction term.
C
In Step 1, BMI is significant (p < .05), so moderation is confirmed.
D
The main effect of exercise becomes non-significant after adding the interaction term, which proves moderation.