Interaction effects

y = b₀ + b₁·x + b₂·m + b₃·x·m

Drag the orange handle (right) to pick a value of the moderator m.

Effect of x when m = 0 (b₁)

Interaction x·m (b₃)

Sample size

Simple slopes ("pick-a-point")

m = −1 SD m = mean m = +1 SD your m

Effect of x across all values of m

95% CI excludes 0 (significant) includes 0

Effects are estimated by OLS on simulated data (x and m standardised, b₂ = 0.3, residual SD = 1). The shaded region boundaries are the Johnson–Neyman points.