Estimating the Impact of Design Standards on the Rigor of a Subset of Single-Case Research

The implementation of research-based practices by teachers in public school classrooms is required under federal law as expressed in the Individuals With Disabilities Education Improvement Act of 2004. To aid teachers in identifying such practices, researchers conduct systematic reviews of the educational literature. Although recent attention has been given to changes in the quality of these reviews, there has been minimal discussion about changes in the quality of the studies that comprise them. Specifically, to what extent have educational policies leading to the creation of experimental design standards resulted in a change in the rigor of educational research? Using a subset of the single-case literature commonly published in special education journals, we estimate the impact of What Works Clearinghouse single-case design standards on the trend in the rigor of single-case studies using a comparative interrupted time series framework. Within this subset of single-case studies, our estimation strategy did not detect a change in the trend of the rigor of single-case research following the establishment of What Works Clearinghouse single-case design standards. Implications are discussed for practitioners and researchers.