Existing approaches to characterise engagement in online learning focus on features of the interaction of students with the learning platform including the number of posts in forums, downloads of learning materials and time spent watching videos. However, little is known about what students actually do within the learning resources and whether these activities are indicators of learning outcomes. To bridge this gap, we associate low-level activity patterns with particular student engagement modes on a connectivist MOOC (cMOOC) that ran for four weeks and involved 224 students. Our findings indicate that our approach isolates meaningful interactive behavioural markers that are indicators of engagement, and are amenable to computation.