OAI-PMH and Benefits of DC

For a while now I have been wondering about metadata interoperability. Günter Waibel and Mary W. Elings demonstrated* that interoperability is possible even if different communities use different metadata standards, or more in the spirit of the article, even if different materials are described by different standards. OAI-PMH is essential for this type of interoperability, but the OAI-MPH is just a tool - a protocol for exchange or sharing, but in fact what makes the exchange possible is Dublin Core.

I was never a big fan of Dublin Core, whether in its qualified or unqualified form. I was always skeptical that the effort to generalize the concept of description and remove it from the material to be described does not bode well for practices in cultural and heritage institutions. However, a title is undeniably a title whether it is the title of a book, or of a painting or of an archival artefact. Based on a descriptive standard, the title does not have to be always constructed the same way and look the same, but basically the concept is understandable - the title is that property under which an object is usually known. Once I accepted this truism, my opposition to DC as an intermediary layer became less intense.

OAI-PMH was one reason I changed my mind, but the other was DigiTool and its mapping file harvesting_schema that is based on the modified extended qualified DC, and which effectively manages to channel data from various metadata standards into descriptive facets that are then present to a user in resource discovery. There is little chance that the user will recognize the native format of the metadata, some residual delimiters may give away a MARC record, but content-wise the harvesting_schema allows for a lot of flexibility. It is also extensible , so one is not bound by the DCTerms set.

When it comes to description, I am in favour of MODS, but I can live with MARC as well, but I started to appreciate the fact that there is a light-weight DC somewhere out there. And I am glad that we can make metadata available in OAI-PMH in both formats in addition to DC elements or more precisely OAI_DC.

*Metadata for All: Descriptive Standards and Metadata Sharing across Libraries, Archives and Museums by Mary W. Elings and Günter Waibel. First Monday, volume 12, number 3 (March 2007), URL: http://firstmonday.org/issues/issue12_3/elings/index.html (Accessed on 2009-10-13)