With this paper we aim to contribute towards an understanding of learning dynamics in doctoral supervision by analysing how learning opportunities are created in the interaction. We analyse interaction between supervisors and doctoral students using the notion of experiencing variation as a key for learning. Earlier research into doctoral supervision has been rather vague on how doctoral students learn to carry out research. Empirically, we have based the study on four cases each with one doctoral student and their supervisors. The supervision sessions were captured on video and audio to provide for verbatim transcripts that were subsequently analysed. Our results illustrate how supervisors and doctoral students create learning opportunities by varying aspects of research in the discussion. Better understanding of this mechanism whereby learning opportunities are created by bringing aspects of variation into focal awareness can help supervisors develop their competences in supervisory pedagogy.