Resource Granularity

Owned by Phil McGachey (Unlicensed)
Last updated: Jan 30, 2015
3 min read

There are a number of options for the granularity at which we could address content. This page serves as a summary of the various approaches.

 

Option 1: Full edX interface

In this mode, the LTI launch will direct a user to a specific resource within the edX course, retaining all the chrome and navigation elements. The LTI launch will both determine the resource to be presented, and provide single sign-on. 

This has the advantage of a relatively simple implementation. However it complicates some other parts of the design, particularly user management. Since a user who enters the system via LTI may have only an anonymous account, and so the behavior of the system when the user follows the various navigation links on the page would have to be defined. Additionally, the full set of navigation elements will clutter the user experience when the edX site is iframed as part of a campus LMS.

 

Option 2: Section navigation

In this mode, the majority of the edX navigation elements and other chrome is removed, but the section navigation is retained.

  • Related units are grouped together.
  • Users can't navigate away from the section, reducing the complexity of the user model.
  • Implementation is relatively straightforward, since existing entry points can be used with only minimal changes to strip out the chrome.

There are a few drawbacks to navigation at the section level:

  • The user experience is cluttered, since the campus LMS (Canvas in this case) may provide its own navigation tools. We end up here with two sets of 'next' and 'previous' arrows, one belonging to edX and the other to Canvas.
  • The course creator is required to use the same sequence of units in a campus course as in the edX original. 
  • The weighting for the grades on each unit are the same for campus and regular edX users.
  • Grade passback is more complicated, particularly when considering regrading.
  • Our design will need to consider the effect of features that modify the contents of a vertical (such as A/B testing or differentiated assignments).

 

Option 3: Unit with discussion forum


In this mode, the unit of granularity is the leaf XBlock, along with any associated discussion forum. 

  • There's no section navigation controls, simplifying the user experience.
  • The campus LMS determines the content and order of the module.
  • Authoring is more straightforward, since there's only one level of navigation.
  • The system design is simplified because there's no section-level features to consider.

There are some potential problems with this case as well:

  • Targeting a leaf XBlock rather than a section may require more development work, since there's no current entry point to the system that does not construct a full vertical.
  • Depending on how the course is structured, there may be many individual LTI launches (and potentially entries in the LMS gradebook) for a section of work.

The discussion forum presents some issues (in this and in the previous options):

  • LTI users are not guaranteed to have a meaningful display name (since we can't insist that PII be passed in the LTI launch).
  • Using edX forums may conflict with existing discussion boards on the campus LMS.
  • Forum contents may or may not be relevant to campus users, depending on the context of the edX course.

 

Option 4: Leaf unit only

This mode is the same as the previous, but with the forum stripped out. This has the same advantages and disadvantages as the previous case, but does not include the extra complication of the discussion board.