Designing Rigorous Group Studies in Special Education: Common Understandings of Effi cacy, Effectiveness, and Evidence Standards

This chapter explores the implications of the recent emphasis on rigorous scientifi c research in education. Our purpose is to provide guidance for special education researchers and professionals about conducting high-quality intervention and evaluation studies relying on the guidelines adopted by the What Works Clearinghouse (WWC) of the Institute of Education Sciences (IES). This type of research will help identify effective practices, programs, and policies that directly improve student learning and development.