Lecture Slides: Power and the Elephant (Understanding the Relation Between Sample Size, Effect Size, and Significance Level)

This activity (created by Dr. Lisa Dinella) has students participate in a lively game show that serves as a metaphor for the relation between sample size, effect size, and significance level when determining power

The goal of this is to provide students with an example that demonstrates the interrelation of effect size, significance level, and sample size as they relate to determining a study’s power. The attached PowerPoint outlines the example and incorporates it into a lecture about power.

However, the example can be taken to the next (and often hilarious) level of having students actually engage in the game show as a class activity (if you choose to do the activity, you should skip slides 5 & 6). This is well worth the time investment as students in our department consistently rave about this game.

Materials.The game show requires two props: a quarter and an elephant. To create the elephant, I cutout the shape of an elephant face from foam board. I then created a trunk by rolling up a gray sheet in the shape of a cylinder and tying it in place with twine. I then tied the trunk to the foam board. I bring in a large gray blanket. It takes two students to “be” the elephant. One holds the foam board in front of his/her face, the other student drapes him/herself with the blanket to be the body. This process took mean hour to create, and it was well worth the effort. Students think the elephant is hysterical, and enjoy acting together to “be” the elephant. The elephant is reusable from one semester to the next.

Please click here for the file.