After reading this chapter, you should be able to

13.1 Contrast the factorial design with the factorial experimental design and choose an appropriate sampling method for the factorial experimental design.

13.2 Identify and design three types of factorial designs.

13.3 Distinguish between a main effect and an interaction.

13.4 Identify main effects and interactions in a summary table and in a graph.

13.5 Articulate the implications of including a quasi-independent factor in a factorial design.

13.6 Illustrate how a factorial design can be used to build on previous research, control for threats to validity, and enhance the informativeness of interpretation.

13.7 Compute a factorial analysis of variance for a between-subjects, within-subjects, and mixed factorial design using SPSS and justify the assumptions required for computing each test.