Conducting research into how students learn is exceptionally difficult. The metacognition required for a student to explain their learning process necessitates drawing on complex conceptual ideas. For international students who are not operating in their first language, the vocabulary involved in such explanations forms a further obstacle. My doctoral action research required the elicitation of explanations from postgraduate international students about the ways, and the extent to which, the use of visual metaphors in lectures contributes to understanding abstract concepts. This was achieved using process interviews. The interviews, conducted in small groups, involved a staged process in which participants completed tasks, then described and evaluated the outcomes from them. While the metacognitive demands were not completely removed, the use of process interviews generated rich data that provided valuable insights into the students’ learning and the circumstances in which visual metaphors helped to unlock meaning. Although presenting the findings from the research is beyond the scope of this paper, it is asserted that these insights would not have been possible without the use of process interviews. This paper provides an evaluation of process interviews as a data collection method.