Using evidence-based practices, or those instructional techniques shown by research to improve student outcomes meaningfully, increases the performance of students with disabilities and should therefore be a priority for special educators. But how does a practice come to be considered evidence based? The unique characteristics of group experimental research (i.e., the use of a meaningful comparison group and the active manipulation of an intervention) allow research consumers to conclude whether an intervention causes desired changes in student outcomes. As such, group experimental research is one type of research that is well suited to determine evidence-based practices. Examples of group experimental research are provided from the contemporary special education literature. (Contains 1 table.)