Open Items from SIMILE/History System Call Today

All -

We had a good discussion about the initial draft of the History System 
descriptive note.  Thanks to everyone who participate, by email or by phone.  
Other than simple errors and omissions, the following topics remain open:

1. The DSpace system uses CNRI Handles to identify certain objects.  Given that 
Handles are generally useful for refering to resources, should the Handle refer 
to the current version of the resource, or to the version current at time of 
creation?  Should Handles be used universally to refer to all objects or just 
those actually retrievable through resolving the Handle?

2. When referring to items that are referenced in the current History System 
output using a database identifier (typically an integer), how should the 
revised History System refer to them?  The descriptive note recommends URIs in 
order to capture metadata about the item, but a few ideas were thrown around 
during the call:

  a. GUIDs - Every item gets a GUID instead of a database ID
  b. URNs - Keep the database ID, but make it part of a URN (e.g. - 
urn:bistream:555)
  c. URLs - If the resource is accessible via a URL, use the URL
  d. Handles - See #1, above

3. It was offered that the History System might apply the RDF-Schema that 
defines the object model to perform inferencing on-write, meaning that 
subproperty values and their parent property values would be stored side-by-
side.  This may have an advantage if the query engine (likely to be Joseki in 
this case) does not support inferencing on its own.  I'd like to ask for 
comments on whether this may be a good idea.  Some observations:

  a. The data stored would not be resilient to changes in the schema, requiring 
a "rebuild" if the schema changes.
  b. The query engine would not need to be schema-aware at all.
  c. The query engine would be isolated from changes in the schema.
  d. The stored RDF models would also be isolated from changes in the schema.

An issue in #3 is whether isolating stored metadata, which was created in the 
context of one version of the schema, /should/ inherit changes to the schema.  
Mark Butler made several valid RDF processing points in a prior post, and that 
information should probably play into this discussion.

Thanks again for your feedback.  I will be working on another draft for early 
next week.

Regards,

Jason Kinner
Dynamic Digital Media, LLC
856.296.5711 (mobile)
215.243.7377 (phone)
jason_kinner@dynamicdigitalmedia.com

Received on Thursday, 8 May 2003 11:37:32 UTC