Looking More Deeply: Fidelity of Implementation as a Critical Component in Evaluating Intervention Impacts

This study investigated the use of fidelity of implementation measures in concert with standardized tests in a matched-pairs, quasi-experimental design for evaluation of a pilot intervention program that was designed to increase second and third graders’ mathematics and reading achievement. Although students in pilot classrooms characterized by high fidelity generally performed at the same level as control students , students in low fidelity pilot classrooms performed at a significantly lower level compared to both control students and students in high fidelity pilot classrooms. We found that the fidelity measures allowed more in depth analysis of the intervention’s component parts and increased the confidence with which the project’s major questions could be addressed, thereby providing more useful information to school district personnel.