Proposal For Metadata Enhancement

This proposal is based on the premis that changes to DSpace metadata characteristics must be backward comparable and retain the same functionality as previously existed to ease transitional for all existing users of the platform.  So many different functional areas of DSpace are reliant on existing metadata functionality, that it is criticial that any changes in functionality also have well defined and scripted updates across releases.

The following are some basic  features of the proposal:

• Metadata fields can include additional properties for
  • Validation rules such as syntax or vocabulary encodings
  • Flag to designate the field is required.
  • Form field types for input forms
  • Type fields to designate Dublin Core or other metadata schema types, types are initially hard coded but new schema registry is extensible
  • MetadataField should be extended with methods to derive its "dc" type. In the absence of an assigned type, all fields default to dc.description typing.
• MetadataSchema filed will be repurposed and extended to support
  • Identification of the types of DSO it may be assigned to
  • DSpaceObjects will be extended to allow them to have a specific "MetadataSchema" assigned. For example, different schema can be created for Publications, thesis, Multimedia, and so on, each having a different set of fields.
  • DSpace will be able to use the new MetadataSchema registry will replace majority of input-forms.xml file.
  • Additional table(s) will more than likely be required to designate schema that can be used in a specific collection, and thus the input forms that may be enabled in that collection.
  • Inheritance may be used in schema to reduce replication of fields. For example, a base schema with Required DSpace fields that are generate during submission, workflow, archive processes (title, issued, accessioned, available)
  • New schema may inherit from it to reduce replication of metadata fields.

Repurposing of MetadataSchema and MetadataField as Custom Metadata Template

Rather than MetadataSchema applying to the namespace of the metadata fields that are allowed by the repository.  We instead recommend that this table be repurposed to embody "templates" of MetadataFields that should be used for specific types of DSpace Objects.   Typing would be based on:

• DSpace Object Types (Site, Community, Collection, Item, Bundle, Bitstream)
• DCMI or Other Classes (Collection , Dataset , Event , Image , InteractiveResource , MovingImage , PhysicalObject , Service , Software , Sound , StillImage , Text)
• Custom Local Representations

Metadata Field Inheritance

Individual Metadata Fields, like DCMI metadata properties will support subTyping or inheritance. For example:

http://dublincore.org/documents/dcmi-terms/#terms-title

In the case of DSpace