Given the ever-expanding array of possibilities, choosing an appropriate research design can be daunting. This chapter introduces a ‘research methods decision tree’, a heuristic that begins with defining the research question, and then systematically leads the reader through a set of decision points, which lead to a method most appropriate for the question. This decision tree covers quantitative, qualitative and mixed methods, and includes examples of EDI research. Quantitative designs include experiments, quasi-experiments, correlational studies and meta-analysis; qualitative designs include integrative literature reviews, conceptual studies (interpretive and theoretical), inductive studies (Delphi, grounded theory, Q method and critical incident analysis), ethnography, narrative studies (storytelling, historiography, oral history, biography and autoethnography) and pure phenomenology. Action research approaches are also addressed. While this heuristic has clear limitations, it can help the researcher avoid the trap of backwards thinking (that is, seizing on a method before clearly defining the research question), while also revealing alternative methods.