PNB 3RM3 Lecture 20: Factorial Designs
6 Oct 2020
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Document Summary
The effect of one independent variable averaged across levels of all other independent variables. Main effects are independent of each other presence of one condition should say nothing about performance when other condition is present. Interaction between a x b: (a1 vs a2) at b1 vs (a1 vs a2) at b2 (b1 vs b2) at a1 vs (b1 vs b2) at a2. If predicting an effect of one variable requires that you know the value of the other. Graphs help with understanding main effects & interactions. **he has a tool to help us with graphs that he"ll share! If comparing daytime and nighttime performance, combine both daytime bars for a single value and both nighttime bars for a single value. Graph on right: may have situations that are 2x4 design; type a and type b (psychotherapy, look at duration of psychotherapy length, 2, 4, 6, 8 weeks of psychotherapy with 2 diff types of therapy.
