Week 10: Complex Experimental Designs

• Factorial Design


  A research design that includes two or more independent variables. These independent variables are called factors.
• Interaction Effects


  An interaction exists between the factors when the effects of one factor depend on the different levels of a second factor.
• Main Effect


  The effect that each independent variable by itself has on the dependent variable (the effect of one independent variable is averaged over the levels of the other independent variables.
• IV x PV Design

  Factorial design including both experimental (manipulated) and non-experimental (measured/manipulated) variables.

  • Useful to look at the combined effect of a situational variable and a personality variable on behaviour.
  • Researchers need be cautious making causal claims involving the participant variable.
• Repeated Measures Design


  The same participants are assigned to all conditions in the experiment.
• • Independent Groups Design: Different participants will be assigned to different conditions.
  • Repeated Measures Design: The sample people will participate in all the conditions.
  • IV x PV: Different people vertically, same people horizontally. People in each row will experience two different variables