The Florida Department of Education (FDOE) identified increasing the graduation rate of students with disabilities and decreasing the graduation gap between students with disabilities and all students as its state-identified measurable result (SIMR). To make progress toward the SIMR, the state sought to build the capacity of local education…

This paper introduces a variation on the post-test only cohort control design and addresses questions concerning both the methodological credibility and the practical utility of employing this design variation in evaluations of large-scale complex professional development programmes in mathematics education. The original design and design…