1. COMPLEX EXPERIMENTAL DESIGNS © 2012 The McGraw-Hill Companies, Inc.

2. Define a factorial design and why a researcher would use this design Describe the information provided by main effects and interaction effects in a factorial design © 2012 The McGraw-Hill Companies, Inc.

3. Describe an IV x PV design Discuss the role of simple main effects in interpreting interactions Compare the assignment of participants in an independent groups design, a repeated measures design, and a mixed factorial design © 2012 The McGraw-Hill Companies, Inc.

4. Provides more information about the relationship than a two level design Can provide us with a curvilinear relationship Inverted-U Comparing Two or More Groups i.e. How dogs, cats, and birds, as opposed to dogs alone, have beneficial effects on nursing home residents © 2012 The McGraw-Hill Companies, Inc.

7. Factorial Designs: Designs with more than one independent variable (or factor) Simplest Factorial Design 2 x 2 factorial design Has two independent variables Each independent variable has two levels © 2012 The McGraw-Hill Companies, Inc.

8. Interpretation of Factorial Designs Main effects of an independent variable Interaction between the independent variables Factorial Designs with Manipulated and Non-manipulated Variables IV x PV designs (Independent Variable by Participant Variable) © 2012 The McGraw-Hill Companies, Inc.

10. Interactions and Moderator Variables Outcomes of a 2 x 2 Factorial Design 1. There may be a significant main effect for independent variable A 2. There may be a significant main effect for independent variable B 3. There may be a significant interaction between the independent variables (See results in following slides) Interactions and Simple Main Effects Simple main effect of type of questioner Simple main effect of type of question © 2012 The McGraw-Hill Companies, Inc.

17. Assignment Procedures and Factorial Designs Independent groups design Repeated measures design Mixed factorial design using combined assignment © 2012 The McGraw-Hill Companies, Inc.

20. Increasing the Number of Levels of an Independent Variable Increasing the Number of Independent Variables in a Factorial Design Repeated measures Mixed factorial design using combined assignment © 2012 The McGraw-Hill Companies, Inc.