Use of the statistical significance test has a long history and has made important contributions to the advancement of adapted physical activity research. However, the statistical significance test has received criticisms for the lack of information it provides regarding clinical relevance. Since outcomes of the “statistical” significant test are functions of treatment effect and sample size, many valuable research questions in adapted physical activity research were arduous to answer due to the difficulty of recruiting a large enough sample. During the last decades, the use of effect size statistics has been given considerable attention as an alterative method of revealing the meaningfulness of research. Effect size is a simple method to quantify the difference between two groups. Generally there two distinct ways to calculating effect size measures: (a) according to group mean differences and (b) according to proportion of variance accounted for. The magnitude of an effect size is often interpreted as “practical” significance. However, the variety of calculating effect size measures creates some confusion on the interpretation on the results. Moreover, during past several years, some researchers in rehabilitation criticized such use of effect size statistics because group means and variance do not indicate the proportion of participants who have improved or recovered as a result of treatment in the clinical setting. They have proposed new statistical approaches, referred to as a “clinical” significance test. The purpose of this presentation is to provide brief overviews of “statistical,” “practical,” and clinical” significant tests and discuss the limitations of each approach. The presentation will conclude by discussing the meaning of the “significance” of research within a framework of adapted physical activity.Keyword(s): adapted physical activity, measurement/evaluation, research