The Challenges of Using Mixed Methods in Requirements Engineering Research

Requirements engineering (RE) concerns the process of eliciting, analysing, specifying, validating and managing software systems' requirements. It combines human and technical aspects of software development. In order to understand the people and the context within which specific actions and decisions take place, RE research studies opt for qualitative approach. On the other hand, such research studies also may need to measure certain variables and verify existing RE theories to complement the understanding through quantitative approach. This nature of investigation necessitates some RE research studies to adopt mixed methods. Despite being challenging, the method enables the strengths of both qualitative and quantitative approaches to be leveraged for comprehending a RE phenomenon. This paper outlines the challenges of employing mixed methods in RE research. The discussion revolves around the experiences of conducting three RE research projects, which each comprised two qualitative and one quantitative studies and integrated two mixed methods research designs. The challenges include formulation of concrete research questions from the start; writing and publishing the findings; mastering the expertise in both approaches as well as understanding the principles underpinning mixed methods. The paper provides a preliminary understanding of the challenges in adopting mixed methods in RE research.