Course structure refers to the type, frequency, and order of resources in a given course. Within an MITx course on edX , course structure is composed of a few base resource types (problems, videos, html pages), each categorized under a specific course component. Figure 1 visualizes the 1143 base resources of 8.MReV in terms of their course component categories, 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.MReV, there were eleven required and three optional chapters (units). Learning Sequences formed the base learning material released in a given chapter, each centered around an interactive eText emphasizing a modeling pedagogy developed by Professor Pritchard and his RELATE group . Each learning sequence comprised a number of html pages (orange) interspersed with checkpoint questions (black). Graded assessment included a combination of Homework (silver) and Quizzes (red) made of mainly numerical and formula response problems, each labeled with a point value correlated to problem difficulty. Supplemental learning components (not pictured in Figure 1) included a threaded discussion forum for students and staff, a staff and student wiki aimed at course resources, and weekly online office hours addressing student questions voted on in the discussion forum (see page 7).
The release of chapters in 8.MReV occurred over roughly 15 calendar weeks, with the final exam ending on August 25, 2013 (and only optional material afterwards). Final course grades were determined by performance on checkpoint questions (10%), eleven homework sets (55%), and eleven quizzes (35%). Certification was granted to students whose final grades were 59% or greater.
To date, MITx courses on edX have had similar schedules of regularly released resources and periodic due dates. Like 8.MReV, courses have used quantitative assessment supported by lecture sequences and textual material, as well as a few special learning components (see end of this report). In the figures that follow, we compare 8.MReV data with those from other MITx courses on edX, from Fall 2012 to Summer 2013.