KMR > E-learning frameworks > Specification development > IMS content packaging
Content Packaging structure
Content Packaging resources
Content Packaging
resources are a structure to group some physical files, and an indication
which one that is the main one (the entrypoint). It also allows you to put
metadata on the grouping as well as on the individual files.
The concept of a CP-resource isn't needed in an RDF binding
Why:
- There is a way of expressing that a resource has parts already in the metadata (dcq:hasPart).
-
If we reference the uri of the main resource directly, we don't need to express
explicitly that this is the main resource (obviously).
- We can annotate each file (rdfs:resource) with metadata using constructs such as
<rdf:Description about="file">.....</rdf:Description>
Content packaging organization and items
Different organizations
may structure/present content in different ways, it might be navigational
paths, groupings with different granularity, different selections or just
reorganizations. An organization is a set of interconnected items where each
item may refer to only one CP-resource and a set of (sub)items. In the information
model the topmost item (the entry point) of an organization is called organization,
from now on lets call it the entry point. In short, the information model
says the following regarding organizations.
- It is allowed to not include any organization at all (in a manifest).
- Different organizations can present the same CP-resources (maybe in I.e. the organizations are not injective.
- Not all CP-resources need to occur in existing organizations. I.e. the organizations aren't surjective.
-
Metadata for a CP-resource that is presentation dependent can be added on
the item that points to the CP-resource instead of directly on the CP-resource.
-
The entry point contains information about the structure this organization
adheres to (only hierarchy is defined in the information model).
- An item can be seen as a container for metadata about groupings (i.e a single resource, subitems or both).
Only organizations is necessarily
Why:
- The entry point can be seen as a specific kind of item, i.e. a subclass.
- We call the common superclass Organization rather than Item since it's more semantically correct.
- A specific subclass is Hierarchy which is a subclass of Graph which in turn is directly inherited from Organization.
- From a Organization dc:hasPart relations points (if nothing else is said) to subOrganizations.
-
The rdf:value relation points to a CP-resource, i.e. a main resource were
it's subsequent hasPart relations (if any) aren't seen as part of the organization
but rather as the file substructure in CP-resources.
-
If an organization points to a resource that isn't an instance of organization
(via dc:hasPart), then it will be treated as if pointed to from an intermediate
organization via the rdf:value and this intermediate organization will have
the same parts (via dc:hasPart) as this resource.
Mail any comments to Matthias Palmer <matthias@nada.kth.se>.