The purpose of this presentation is to provide an overview of critical issues related to conducting research in adapted physical activity, especially as it relates to experimental/quasi-experimental and correlational designs. Conducting physical activity research on participants with disabilities poses unique challenges. These challenges include measurement, heterogeneity of participants, sample size and generalizability, among others. It can be argued that conducting research in adapted physical activity is complex and because of its complexity can be viewed as difficult to conduct. This is especially true when studies are conducted in applied settings (e.g., educational). In order to effectively deal with these issues, alternative quantitative research methodologies can be employed (e.g., single-subject) and may better fit certain research contexts and participant demographics. Critical issues need to be addressed if adapted physical activity research is to ultimately verify techniques, practices, and programs as evidence-based. Keyword(s): adapted physical activity, measurement/evaluation, research