We sketched a conceptual data model as a preliminary step to move into implementation (according to this article, this model is conceptual). Highlighted are content classes, their relationships, and corresponding sources. In later models (logical models, including relational models) we can address data fields in detail.
Entities in the diagram represent content types (sky-blue rectangles), relationships (light beige ovals), and links along with their multiplicity.
The diagram is divided into three blocks:
- The big main block circumscribes content types that fit fairly well into a relational model. Content types in this block have clear (and probably fixed) relationships with eachother. In Drupal, this relational nature makes it plausible to hard-code these relationships as node reference fields in the conrresponding content types.
- The other two blocks encircle content types holding data items that could be related to any piece of content. This fuzzy association invites us to go about implementing this using Drupal taxonomies or free node reference fields.