Data from edX platform is primarily stored in JSON logs. A fundamental axis which is used to record precisely the activity performed by the learner is an “event type”. Multiple “event types” differentiate between different activities done by the learner. We base our software on this fundamental axis. Below we provide detailed description of how each event type is translated into an entry in MOOCdb. This detailed information gives researchers and plaform providers information about MOOCdb translation and how data is mapped syntactically and semantically.