Chapter Summary

This chapter provides an overview of experimental design from basic ex post facto designs through to sophisticated factorial designs. The concepts of random assignment and control are introduced along with discussion of the special contribution experimental design makes to assessing causal relationships among variables. A campus-based organizing example that illustrates increasingly sophisticated experimental design runs through the chapter.

Chapter Objectives

This chapter will help you:

• Identify the advantages and disadvantages of experiments as research methods.
• Describe the basic experimental design.
• Explain the concept of control in experimental design.
• Discuss the concept of random assignment in experimental design and why it is important.
• Compare and contrast time series analysis with basic experimental design.
• Explain the concept of factorial design in experiments.
• Compare and contrast between-subjects and within-subjects experimental design.
• Explain the concept of validity in experimental design and identify the threats to validity.