For example, an HTML page that has embedded links to other content is not atomic in delivery , since delivering it to a student potentially requires delivering additional content. Originally, we considered modules as compositions of granules . But as we looked at the issues of providing templates to support Legacy, or design patterns governing modules more generally, we decided that we needed a containment concept within modules . For Legacy, not only would such a concept allow us to reduce the visual complexity of delivery plans for an entire module , but it would also provide guideposts for populating corresponding HTML delivery templates. Granule references solve this problem by allowing the delivery of granules to be authored within phases, but their associations with learning objectives, taxonomies, and metadata to be described at the module level.
Modules retain their previous status as components of courses .
However, the introduction of mosaics in CAPE means that modules can also be components of mosaics . Mosaics are notionally a collection of challenge-based modules unified by some overarching challenge. The reason that granules can appear at any level in the hierarchy stems from a role I described for them at the Austin ERC meeting. The content in a granule can serve the role of setting context . It can tell what a course or mosaic or module is about, what lies ahead, what options will be presented, etc.