Communication disorders: a power analytic assessment of recent research

This study assessed the relative statistical power of contemporary research in communication disorders. Results of the analysis, based upon an evaluation of two major journals, revealed overall mean power figures of 0.16, 0.44, and 0.73 for small, medium, and large effect sizes, respectively. Interdisciplinary comparisons indicated that low statistical power is not unique to research in communication disorders, but is apparent in other behavioral science areas as well. Several alternatives are offered to the researcher who will want to ensure sufficient power for his investigation on an a priori basis. The implications of this study are discussed in reference to the experimenter/clinician model.