PS295 Lecture Notes - Lecture 17: Line Graph, Complement Factor B
Document Summary
When calculating main effects, we use marginal means (add two cell means together, divide by. When calculating interaction effects, we use cell means (subtract cell means from each other) Dependent measures are always on the y axis. Possible patterns of results (8 patterns) for a 2x2 matrix: No interaction effect: no main effects, main effect of a only, main effect of b only, main effect of a and b. Interaction effect: no main effects, main effect of a only, main effect of b only, main effect of a and b. In this graph, there is no effect of a or b. A: stack the two bars in each level on top of each other (the red and blue together) and if they are the same height there is no difference. B: stack each colour on each other (red on red, blue on blue) if theres no difference/they are same height there is no main effect of b.
