As the Open Archive Initiative Protocol for Metadata Harvesting has become a central component of digital library projects, increased attention has been paid to the ways metadata can be reused. As every computer project since the beginning of time has had occasion to understand, the data available for harvesting is only as good as the data entered. Given these quality issues, there are larger questions about how to reuse the valuable metadata once it has been originally described, cataloged, annotated, and abstracted.
Squeezing metadata into a juicer
As is often the case, the standards and library community were out in front in thinking about how to make metadata accessible in a networked age. With the understanding that most of the creators of the metadata would be professionals, choices were left about repeating elements, etc., in the Dublin Core standard.
This has proved to be an interesting choice, since validators and computers tend to look unfavorably on the unique choices that may make sense only locally. Thus, as the weblog revolution started in 2000 and became used in even the largest publications by 2006, these tools could not be ignored as a mass source of metadata creation.
Reusing digital objects
In the original 2006 proposal to the Mellon Foundation, Carl Lagoze wrote that “Terms like cyberinfrastructure, e-scholarship, and e-science all describe a concept of data-driven scholarship where researchers access shared data sets for analysis, reuse, and recombination with other network-available resources. Interest in this new scholarship is not limited to the physical and life sciences. Increasingly, social scientists and humanists are recognizing the potential of networked digital scholarship. A core component of this vision is a new notion of the scholarly document or publication.
Rather than being static and text-based, this scholarly artifact flexibly combines data, text, images, and services in multiple ways regardless of their location and genre.”
After being funded, this proposal has turned into something interesting, with digital library participation augmented by Microsoft, Google, and other large company representatives joining the digital library community. Since Atom feeds have garnered much interest and have become a IETF recommended standard, there is community interest in bringing these worlds together. Now known as the Open Archives Initiative for Object Reuse and Exchange (OAI-ORE), the alpha release is drawing interesting reference implementations as well as criticism for the methods used to develop it.
Resource maps everywhere
Using existing web tools is a good example of working to extend rather to invent. As Herbert van de Sompel noted in his Fall NISO Forum presentation, “Materials from repositories must be re-usable in different contexts, and life for those materials starts in repositories, it does not end there.” And as the Los Alamos National Laboratory Library experiments have shown, the amount of reuse that’s possible when you have journal data in full-text is extraordinary.
Another potential use of OAI-ORE beyond the repositories it was meant to assist can be found in the Flickr Commons project. With pilot implementations from the Library of Congress, the Powerhouse Museum and the Brooklyn Museum, OAI-ORE could play an interesting role in aggregating user-contributed metadata for evaluation, too. Once tags have been assigned, this metadata could be collected for further curation. In this same presentation, van de Sompel showed a Flickr photoset as an example of a compound information object.
Anything but lack of talent
A great way to understand the standard is to see it in use. Michael Giarlo of the Library of Congress developed a plugin for WordPress, a popular content management system that generates Atom. His plugin generates a resource map that is valid Atom and which contains some Dublin Core elements, including title, creator, publisher, date, language, and subject. This resource map can be transformed into RDF triples via GRDDL, which again facilitate reuse by the linked data community.
This turns metadata creation on its head, since the Dublin Core elements are taken directly from what the weblog author enters as the title, the name of the weblog author, subjects that were assigned, and the date and time of the entry. One problem OAI-ORE problem promises to solve is how to connect disparate URLs into one unified object, which the use of Atom simplifies.
As the OAI-ORE specification moves into beta, it will be interesting to see if the constraints of the wider web world will breathe new life into carefully curated metadata. I certainly hope it does.