A Practical Guide to Teaching Measures of Effect Size in Physical Therapist Education

Background and Purpose. 

Evidence-based practice (EBP) is a key component of physical therapist (PT) education. Effect size is an increasingly important concept in EBP because effect sizes enable the comparison of results between studies and may provide measures of clinical significance. Effect sizes are also an important part of meta-analytic techniques. Knowledge of effect sizes will therefore help students to critically appraise research findings and will enhance EBP education. The purpose of this paper is to review commonly used effect sizes and to present opportunities for related learning activities. A variety of common measures are reviewed and discussed.

Position and Rationale. 

It is our position that a detailed, yet balanced presentation of effect sizes should be included in PT education curricula. To interpret effect sizes accurately, students should be familiar with the underlying concepts, nuances, and limitations of each measure. The effect size literature can be complex but we present several learning activities that would be appropriate for PT education.

Conclusions. 

We support and encourage the use of effect sizes in research reporting and PT education. Students at the doctoral level should receive enough curricular content on effect sizes so that they can interpret and apply the concepts appropriately.