Professional practice guided by the best research evidence is a usually referred to as evidence-based practice. The aim of the present paper is to describe five fundamental beliefs of adapted physical activity practices that should be considered in an 8-step research model to create evidence-based research in adapted physical activity. The five beliefs are individualization, critical thinking, self-determination, program effectiveness, and multifactor complexity. The research model includes conceptualize the problem, conduct research on the process of the problem, conceptualize and specify the intervention, evaluate intervention outcomes, evaluate intervention processes, determine person-by-treatment interactions, determine context-dependent limitations, and investigate factors related to intervention adoption maintenance. The eight steps are explained with reference to two research programs that used a randomized control group design. (Contains 1 table and 1 endnote.)