Course structure refers to the type, frequency, and order of resources in a given course. Within an MITx course on edX , course structure is made up of a few base resource types (problems, videos, html pages), each categorized under a specific course component. Figure 1 visualizes the 1158 resources of 8.02x ordered according to their appearance in the course, where each line indicates a separate resource, and the length approximates the weight of the component toward final course grade (lecture sequences do not count). Text labels indicate selected chapters, which are the highest level on the “courseware” menu that houses the course content.
Figure 1. (Top) Course structure visualization highlighting course resource density, where the y-axis represents the temporal order of resources in the course. (Bottom) A legend providing context for each course component.
For 8.02x, Lecture Sequences formed the base learning material released in each chapter. Each sequence consisted of videos (orange) taken from Professor Lewin’s on-campus lectures at MIT in 2002, with every video followed by a checkpoint question (black). Homework (silver) and examinations (red) made up of numerical and formula response questions provided high-level assessments similar to those in the residential version of the course, 8.02. Supplemental learning components included interactive simulations (green) designed by Professor Belcher for TEAL at MIT, and problem solving tutorial videos (blue) from Professor Lewin. Supplemental learning components not pictured in Figure 1 included a threaded discussion forum for students and staff, a student- and staff- edited wiki, and eText based on notes from the residential course, 8.02 (Liao, Dourmashkin, and Belcher ).
The weekly release of chapters in 8.02x occurred over 17 calendar weeks, about the same length as the MIT residential version. Grades in 8.02x were determined by nine homework sets (18%), three midterms (15% each), and a final exam (30%). The lecture sequences (5%) and TEAL simulations (2%) had smaller weights but were graded to encourage participation. Certificates were granted to students whose final grades were 60% or greater.
To date, MITx courses on edX have had similar schedules of regularly released resources and periodic due dates. Like 8.02x, other courses have used quantitative assessments, lecture sequences, and textual material, as well as a few learning components unique to particular courses (see end of this report). In the figures that follow, we compare 8.02x data with those from other MITx courses on edX, from the Fall of 2012 to the Summer of 2013.