In this article, third generation cultural historical activity theory (CHAT) (Engeström, 2011) will be the means for analyzing tensions and contradictions between formal and informal learning within a MOOC design. This article builds on previous work (Bradshaw et al., 2017) wherein CHAT was used to establish formal and informal learning as activity systems. Formal and informal learning are considered in relation to designing learning for a MOOC environment. Findings from an "in situ" study specifically examining CHAT elements in the process of design are considered in a movement towards making visible what those tasked with designing courses normally do not see in relation to informal learning. Implications for practice are presented in a CHAT-informed MOOC design model intended to augment typical approaches to instructional design. The outcome is an argument for CHAT-informed MOOC design model that can intentionally address both formal and informal opportunities for learning.