This case centers on a longitudinal case study carried out between 2011 and 2012 as part of an EdD qualification. The study sought to chart the journey of understanding of a group of student teachers in relation to their conceptions of the role of theory and practice in learning to become a teacher. Two distinctive features of the research methodology are the fact that I was researching elements of my own practice (as a teacher educator) and the longitudinal nature of the study. In this case, I focus primarily on issues of research design and methodological tensions judgments pertaining to these facets of the study. The case discusses the rationale for a longitudinal case study and the way that diverse data collection methods were combined in its implementation. Thorough preparation and clarity of research design are considered alongside the role of judgment in the face of emergent issues and uncertainties in order to provide a realistic account of the process. Distinctive issues arising, such as the need for reflexivity and strong research relationships, are discussed and a number of practical implications and lessons highlighted.