Translation process research (TPR) is an atheoretical label used to describe research within cognitive translation and interpreting studies (CTIS) devoted to the study of the cognition involved in multilingual mediated communication with written source texts. Research methods are a pivotal issue in TPR, where researchers’ main aim is to develop rigorous, reliable methods to access the evidence of the workings of translators’ minds. Moreover, the drive in TPR for advancing fast and catching up with the pace of other cognitive science disciplines has resulted in a profusion of research topics, data coding, and tools. This chapter provides a snapshot of research methodology in TPR with an eye to identifying limitations, challenges, and opportunities for improvement. After introducing some basic notions related to quantitative and qualitative research, it focuses on three key types of research in TPR: quasi experimental, observational, and the cognitive research of texts. Each type is briefly contextualized and defined in relation to the theoretical paradigm it adheres to, its contexts of application and topics, and the data collection and analysis methods most frequently employed. Core results and critical issues are also discussed. The chapter closes with a few recommendations for practice.