16: Integrating impact evaluations and implementation and process evaluations in mixed methods research in education

The importance of integrating impact evaluations (IEs) and implementation and process evaluations (IPEs) is explored through four published examples that combine research designs and quantified and qualitative data. The chapter demonstrates the importance of embedding IPEs within IEs, using randomised controlled trial (RCT) designs and regression discontinuity designs (RDDs), to provide answers to efficacy, effectiveness, implementation and process research questions. It explores concordant, discordant, mixed, and inconsistent results between the IEs and IPEs, demonstrating that mixed methods are feasible and highly desirable in undertaking evaluations of educational interventions using these designs. By discussing four ‘real life’ evaluations which combined IEs and IPEs, the chapter shows that integrated IEs and IPEs can support the underpinning logic model or prove to be inconsistent with it. The key implication for doing mixed methods research in education evaluation is that IPEs should always be embedded within IEs, when planning, designing, conducting, and reporting RCTs or RDDs.