The success of the flipped classroom (FC) is effectively reliant on the level of student engagement with the preparatory activities prior to attending face-to-face teaching sessions. Information about the nature and level of student engagement with these activities can help instructors make informed decisions regarding how to best support student learning. Despite the comprehensive data collection enabled by the increasing presence of education technologies, few studies have used these data to investigate the range of strategies students employ in FC models. This study addresses this deficit by proposing an analytical approach that allows for exploring, first, the strategies students use to interact with online preparation activities; and, second, evolution of those strategies over the duration of a course delivered with a FC pedagogy. The proposed approach identified eight learning strategies and six trajectories of strategy change over the duration of the course, with statistically significant effects of strategy change trajectories on academic performance.