The new OAI-PMH interface to Nature.com sports one particular novelty which may well be of interest here: it makes use of the PRISM Aggregator Message. (For an announcement of this service see the post on our web publishing blog Nascent.)
As a protocol for the harvesting of metadata records within a digital repository, OAI-PMH records may be expressed in a variety of different metadata formats. For reasons of interoperability a base metadata format (‘Dublin Core’) is mandated for all OAI-PMH implementations. The expectation is that this base format would be augmented by community-specific vocabularies.
Our natural inclination was to mirror the article descriptions which we already circulate in our RSS feeds and within our HTML pages (as META tags) and PDF files (as XMP packets). In these cases we have used open data models (e.g. RDF) with simple properties cherry-picked from the DC and PRISM namespaces. But OAI-PMH has a special ‘gotcha’ in this regard: any metadata format must allow for W3C XML Schema validation. That is, the properties need to be constrained by an XSD data model. Enter PRISM Aggregator Message (PAM).