Equivalence Testing

Definition: Equivalence tests statistically assess the null hypothesis that a given effect exceeds a minimum criterion to be considered meaningful. Thus, rejection of the null hypothesis provides evidence of a lack of (meaningful) effect. Based upon frequentist statistics, equivalence tests work by specifying equivalence bounds: a lower and upper value that reflect the smallest effect size of interest. Two one-sided t-tests are then conducted against each of these equivalence bounds to assess whether effects that are deemed meaningful can be rejected (see Schuirmann, 1972; Lakens et al., 2018; 2020).