Chapter 8: Experimental Design

When you think of the term experiment, what comes to mind? Perhaps you thought about trying a new soda or changing your cat’s litter to a different brand. We all design informal experiments in our life. We try new things and seek to learn how those things changed us or how they compare to other things we might try. We even create entertainment programs like Mythbusters whose hosts use experimental methods to test whether common myths or bits of folk knowledge are actually true. It’s likely you’ve already developed an intuitive sense of how experiments work. The content of this chapter will increase your existing competency about using experiments to learn about the social world.

LEARNING OBJECTIVES

• Understand when experiments may be appropriate
• Understand the basics of true experimental designs
• Be able to identify “pre-experimental” and “quasi-experimental” designs
• Understand the limitations of various experimental designs
• Be able to explain the logic of experimental design
• Understand threats to the internal and external validity of experimental designs