In this commentary, the issue of fidelity assessment is addressed as it relates to Strain and Bovey's article (2011). Four reasons are provided for measuring fidelity in intervention studies. Measuring fidelity (a) potentially allows investigators to document the findings were not due to the lack of fidelity in a study; (b) presents information…

The paper maintains that impact evaluation studies of programs serving handicapped infants and preschoolers should be restricted to scientifically defendable investigations. Specific types of impact studies and an evaluation process are suggested. It is suggested that program leaders should focus evaluation activities on the status of project…

This paper considers methodological issues related to the independent variable in early intervention research. Three standards are proposed: (1) use theory to guide research; (2) provide operational definitions of independent variables, quantify them, and describe how they relate to theory; and (3) measure treatment fidelity. Three levels of…

Issues are raised about the Council for Learning Disabilities Research Committee's standards for describing research subjects, including justification for the recommended standards, relationship between description of subjects and probability of replication, and impact of the type of research on subject description standards. Recommendations are…