Equivalence tests for one-way independent groups designs

Researchers in education are often interested in determining whether independent groups are equivalent on a specific outcome. Equivalence tests for 2 independent populations have been widely discussed, whereas testing for equivalence with more than 2 independent groups has received little attention. The authors discuss alternatives for testing the equivalence of more than 2 independent populations, and the use a Monte Carlo study to demonstrate and compare the performance of these alternatives under several conditions. The results indicate that a 1-way test (e.g., Wellek’s F test) is recommended for assessing the equivalence of more than 2 independent groups because approaches based on conducting pairwise tests of equivalence are overly conservative.