Schemas used for DLF Aquifer - Asset action experimentation -- April 2006

To facilitate development of the DLF Aquifer Technology Working Group's Asset action experimental portal, which was first presented publicly at the DLF Spring 2006 Forum (April 2006, Austin, TX), three XML schemas were developed to support harvesting of asset action packages using the OAI Protocol for Metadata Harvesting. Schemas were written in W3C XML Schema Language and were designed to allow simultaneous harvesting of asset action packages in combination with other descriptive metadata expressed using either simple Dublin Core or MODS semantics. The relevant schemas:

1. http://gita.grainger.uiuc.edu/AquiferTechWG/assetactions.xsd -- this schema declares the XML semantics and structures used for expressing an arbitrary asset action package (i.e., set of "actionable" URLs) associated with a particular digital resource.
    
   
2. http://gita.grainger.uiuc.edu/AquiferTechWG/aquifer_dc.xsd -- this schema imports schema 1 and declares an element that wraps together a simple DC metadata record and an asset action package in a way suitable for harvesting using OAI-PMH.
    
   
3. http://gita.grainger.uiuc.edu/AquiferTechWG/aquifer_mods.xsd -- this schema imports schema 1 and declares an element that wraps together a MODS metadata record and an asset action package in a way suitable for harvesting using OAI-PMH.
    
   

The current (April 2006) version of the experimental portal only supports resources of type "basic image" (e.g., digitized photos, posters, etc.). A more prescriptive XML schema was created constraining names, labels, and format attribute values to only those used for actions and actionGroups associated with the basic image resource type. This more prescriptive schema is useful during metadata workflow development for validating conformance of asset action packages for inclusion in the experimental portal. It is available at: http://gita.grainger.uiuc.edu/AquiferTechWG/assetactions-v1.3b.xsd. An example of a basic image asset action package that conforms to this schema (and to the more lax assetActions.xsd) is available at: http://gita.grainger.uiuc.edu/AquiferTechWG/sampleassetaction.xml.

Alternative schema strategies have also been discussed, including an assetAction schema that more strongly types assetGroup element declarations to allow explict definition of each kind of actionGroup and enummeration of each kind of action associated with each actionGroup type individually (requires use of xsi:type attributes in lieu of name attribute for actionGroup elements), and an assetAction schema that replaces some actionGroup and action element attributes with roughly equivalent attributes from the XLINK namespace. Also considered was a wrapper schema for use with OAI which would allow use of any descriptive metadata schema in combination with asset action package structure (rather than specifying oai_dc or MODS at the wrapper schema leval), and the option of harvesting asset action packages on their own (i.e., separate from other descriptive metadata). There are no immediate plans to explore any of these options further at this time, though they remain viable for possible future consideration.

Page last updated 26 April 2006 by twc.