This article sets the context for the development of research quality indicators and guidelines for evidence of effective practices provided by different methodologies. The current conceptualization of scientific research in education and the complexity of conducting research in special education settings underlie the development of quality indicators. Programs of research in special education may be viewed as occurring in stages: moving from initial descriptive research, to experimental causal research, to finally research that examines the processes that might affect wide-scale adoption and use of a practice. At each stage, different research questions are relevant, and different research methodologies to address the research questions are needed.