A Simple Classroom Demonstration of Power

• In Event: Teaching Educational Research Methods: Lessons and Opportunities

Abstract

The notion of statistical power seems to elude students in research methodology and statistics courses. Illustrating the notions of α, β, and Power through truth tables, or showing them how to calculate power through software such as Gower and Sample Power seems to help little. The suggestion and illustration here is to use one of our simplest measurement techniques, the Likert-type item, in class, to help students gain some intuitive understanding of the relationship between Power and N. This will also introduce students to a rarely used inferential procedure that can be used to test “lean” for single Likert-type items. A test of Disagreement on a single Likert-type item is also available. The demonstration’s emphasis is facilitating comprehension.

Authors

• Mary G. Lieberman, Florida Atlantic University

• John D. Morris, Florida Atlantic University