Two recent studies (Meikle et al. (79), David et al. (82)) have compared the efficacy of aphasia therapy offered by speech therapists and by unqualified volunteers finding no difference in the progress of patients assigned for treatment to these two groups. This conclusion is however based upon the acceptance and not the rejection of the null hypothesis. Since the study of treatment efficacy is principally handicapped by the large variability of both patients and their response to treatment this appears to be an unsatisfactory methodology. Further examination of these papers reveals a number of factors which may favour the null hypothesis. The conclusion drawn from this research is therefore both unfair and disheartening to the speech therapy profession. Furthermore since the methodological problems encountered in these studies are likely to be common to all group studies of treatment, the investigation of specific treatments with individual patients is recommended as a better approach to the problem.