Fidelity of Implementation: An Overlooked Yet Critical Construct to Establish Effectiveness of Evidence-Based Instructional Practices

The discipline-based education research (DBER) community has been invested in the research and development of evidence-based instructional practices (EBIPs) for decades. Unfortunately, investigations of the impact of EBIPs on student outcomes typically do not characterize instructors' adherence to an EBIP, often assuming that implementation was as intended by developers. The validity of such findings is compromised, since positive or negative outcomes can be incorrectly attributed to an EBIP when other factors impacting implementation are often present. This methodological flaw can be overcome by developing measures to determine the fidelity of implementation (FOI) of an intervention, a construct extensively studied in other fields, such as healthcare. Unfortunately, few frameworks to measure FOI in educational settings exist, which likely contributes to a lack of FOI constructs in most impact studies of EBIPs in DBER. In this Essay, we leverage the FOI literature presented in other fields to propose an appropriate framework for FO I within the context of DBER. We describe how this framework enhances the validity of EBIP impact studies and provide methodological guidelines for how it should be integrated in such studies. Finally, we demonstrate the application of our framework to peer instruction, a commonly researched EBIP within the DBER community.