VT-ETD Initiative

We have added on an OAI interface to the central VT-ETD collection by interfacing directly with the main ETD database. The OAI-PMH URL is registered with the OAI central site and may also be found on the Repository Explorer (http://purl.org/net/oai_explorer).

This was much more work than anticipated, because we had to deal with character set incompatibilities. It seems that the ETD database contains ASCII, Extended-ASCII, Unicode-style character entities, ISO-8859/1 entities and non-XML-parsable characters, and the communication among other components wasnt quite straight-forward either.

We eventually ended up with the following data flow to browse through the repository using the explorer:
ETD-Database
-->(multi-format)--> OAI-PMH interface
... via web server 1
-->(7-bit ASCII with XML/character entities)--> Expat XML parser
-->(UTF-8 with entities substituted)--> OAI Compliancy program
... via web server 2
-->(8-bit ASCII with HTML/character entities reinstituted) --> browser

There were many format conversions and a fair deal of data cleaning. No notion of partitions was adopted so the database is still flat. Four metadata formats are supported: DC, ETDMS, RFC1807, and MARC21. Also, the code that was written to make the VTETD collection into an OA has been generalized to work with any installation of the ETD-db software. More information on all of this can be found on the NDLTD website and on the ETD-db OAI Extensions page