Design-based research (DBR) systematically investigates and develops innovative solutions to complex educational problems. We argue that DBR intervention studies intrinsically employ mixed methods to collect, analyze, and interpret data. Drawing on a 3-year DBR project (2015–2018) implementing a social studies/history curriculum in self-contained special education classrooms, we conceptualize Transformative Mixed Methods Design-Based Research (Transformative MM-DBR). The central contribution of this methodological article is to articulate Transformative MM-DBR as an equity-oriented mixed methods typology that systematizes multi-phase integration of qualitative and quantitative strands. We outline the rationale for mixed methods in special education, illustrate the design of a disciplinary literacy intervention for students with learning differences, and offer core tenets for researchers adopting this paradigm.
Claravall et al. (Sat,) studied this question.