While there has been a lot of attention about the potential for MOOCs to transform higher education, far less empirical research has been conducted that explores the experiences and behaviours of learners in these online settings. A particular strength of MOOCs is the potential for thousands of learners to come together to learn. Understanding who interacts, how they interact, and why is an important part of understanding how learning may occur. This presentation aims to highlight the different ways in which people communicate and interact with one another in MOOCs, and how these interactions are related to learner characteristics, experiences and outcomes through the in-depth mixed method analysis of one case study MOOC. The findings discussed are those emerging from an ongoing study funded by the Bill and Melinda Gates foundation. See http://www.oii.ox.ac.uk/research/projects/?id=121 for more details.