Augmented Metadata and Annotations

From Metadata-Registry
Revision as of 07:31, 25 October 2005 by Diane (Talk | contribs)

Jump to: navigation, search

Outline--a harvest scenario

  1. We publish two metadata formats designed to support annotations and augmented metadata
    • The key feature of these formats is two metadata elements, one (and only one) of which must be present, either of which may be repeated:
      • xxxxUniqueIdRef? -- which contains a reference to an existing metadata record in the MR and must match an existing record
      • dcIdentifierRef? -- which contains a reference to a URI that may or may not exist in the MR. #*Augmented metadata must reference an existing URI in the MR. This could also be expressed as <reference type=xxxxUniqueId?> or <reference type=dcIdentifier>
    • These are intended to be used to supply annotations and augmented metadata for harvest via OAI and perhaps a services interface.
  2. Annotation and augmentation suppliers wishing to supply metadata about a resource identified by a URI should first query or harvest the MR to get a list of metadata records that are about that URI.
  3. They create metadata about their annotation in the above format and serve it via OAI. This record may carry the actual annotation or it can simply contain a reference. In the case of metadata augmentation, each record served should be a self-contained, incomplete metadata record and should not reference another source of metadata.
  4. We harvest the records through a standard harvest -- all incoming records will have to be associated with a collection record
  5. The ingest process creates a unique mrec record for each incoming record
  6. References in the MR must always be mrec_ids so in the case of dcIdentifierRef? the ingest process retrieves all mrecs that reference each dcIdentifierRef?.
  7. If a dcIdentifierRef? references a URI that is not found, an mrec record is created for that URI and is queued for metadata generation by iVia (controversial)
  8. An entry is created in the link table for each mrec identifed either directly or by reference. This will contain the mrec_id of the annotation record, the mrec_id of the mrec being annotated, a reference type, a datestamp, and a source mrec_id
    • Note that the link table will need an additional 'source' field that will, in the case ofannotations and augmentations, contain the mrec_id of the annotation or augmenation metadata record that supplied the link.
    • Note also that reference type and datestamp are denormalized values that can be determined by reference to the source mrec_id if necessary.
  9. Output of augmented metadata is the tough thing -- it needs to be served both as a component part of the metadata format being augmented and as a distinct format, both within and without the mudball.

[NOTE: Pull Augmentation Use Cases for this section]