Friday, November 6, 2009
Back to the Fedora: Part 4
This is the final post in the series.
So far we have introduced a pair of Content Model objects: one for social science data, and one for social science data documentation. In this post we introduce a third Content Model object for social science: an aggregate level object that has some content of its own (descriptive metadata and preservation metadata), but serves largely to group together related objects.
The Content Model object is to the left. It must have two Datastreams: one for the descriptive metadata in DDI XML format, and one for preservation metadata in PREMIS XML format. Note that we may discover that we can use DDI for both purposes, and in that case, the PREMIS Datastream will drop out as a required element.
Like past posts, the image to the left is a link to the ICPSR Fedora test repository, and will return the "home page" for the Content Model object pictured.
To the right we have a Fedora data object which conforms to the Content Model above.
Like the Content Model image, this image is also a link to our Fedora test repository, and clicking it will navigate to the matching data object.
This object has one relationship asserted per member object. In this case we assert three hasMember relationships: one for the survey data object; one for the survey documentation object; and, one for the survey instrument object. These correspond to isMemberOf relationships asserted in those objects, and together they assert a series of bilateral relationships.
The object contains the two required Datastreams. In this case the actual XML is somewhat stylized, and may not be "clean" XML. In particular the PREMIS Datastream is very much a work in progress here at ICPSR, and may bear little resemblance to high-quality PREMIS XML.