Dear Bernard and List, My apologies for not responding sooner; I'm impossibly behind in reading listserv email. Comments below.
> Riley, Jenn wrote: > > > The Variations/FRBR [1] project at Indiana University has released > > bulk downloads of metadata for the sound recordings presented in our > > Scherzo [2] music discovery system in a FRBRized XML format. > > > Before digging into this any further, one question: How is the > linking between works and expressions effected? On first inspection, > I find nothing in the expression data that would indicate the work. The XML format that defines this data (our project "efrbr" definition; more information at <http://www.dlib.indiana.edu/projects/vfrbr/schemas/1.0/index.shtml>) doesn't have the concept of a "record," just "entities" and "relationships". The XML wrapper can include any combination of entities and relationships - there's no requirement that it be, say, Work-centric (show one Work and all the other FRBR entities with relationships to that Work) or Manifestation-centric (show one Manifestation and all the other FRBR entities with relationships to that Manifestation), though you could easily use the format for either of those purposes. Therefore the big .xml file that has all the Expression data doesn't *have* to have relationships between Expressions and Works to be valid. We simply chose to arbitrarily break the data into individual XML files by entity and relationship type, since there was enough data we knew we had to split it up somehow to keep the file size to something remotely manageable, so this seemed logical. It's just the raw data - a system using it could index and store and update it however it likes. All the relationships are there, though, spread across all of the files. Relationships between Works and Expressions can be found in the file realizedThrough.xml. > I suspect the link to be via the file realizedThrough.xml, because > between manifestation and expression, there's the file embodiedIn.xml > which seems to be the link between the two. However, I'd have expected > the relationship between E and M to be 1:n, yet it seems to be > the opposite. > Can you elaborate on this matter? You've switched to talking about the relationship between Expression and Manifestation rather than Expression and Work, so I'm a bit confused as to what you're asking, but I'll give it a shot. You're correct that embodiedIn.xml lists relationships between Expression and Manifestation. (Note "realized through" and "embodied in" are terms right out of the FRBR report to describe these relationships.) The relationship between Expression and Manifestation is n:n (many to many). A given Expression be embodied in any number of different Manifestations, and a given Manifestation may embody any number of different Expressed Works. In embodiedIn.xml, each element <efrbr:embodiedIn> describes the relationship between one Expression and one Manifestation. This statement, however, doesn't mean that's the only Manifestation of that Expression, or the only Expression that appears on that Manifestation. Instead, these are just tiny statements of fact. To find all the Expressions on a given Manifestation (which is only one of the many questions one might want to ask of this data), you'd need look for all of the <efrbr:embodiedIn> statements that have the URI for the Manifestation you care about in the @target attribute. You can see some of these right at the beginning of the file: <efrbr:embodiedIn source="http://vfrbr.info/expression/1"; target="http://vfrbr.info/manifestation/1"/> <efrbr:embodiedIn source="http://vfrbr.info/expression/2"; target="http://vfrbr.info/manifestation/1"/> <efrbr:embodiedIn source="http://vfrbr.info/expression/3"; target="http://vfrbr.info/manifestation/1"/> <efrbr:embodiedIn source="http://vfrbr.info/expression/4"; target="http://vfrbr.info/manifestation/1"/> To find all the Manifestations a given Expression appears on, you'd look in the data for all the <efrbr:embodiedIn> statements that have the URI of the Expression you care about in the @source attribute. Basically it's a whole bunch of very atomic data that can be combined in any way to answer all sorts of different questions: What Works are by this Person? What Manifestations were published by publisher X? What Works were performed by Corporate Body X (i.e., which Works have Expressions that have realized by relationships to that Corporate Body)? Ad infinitum... > Many thanks, > B.Eversberg Hope this helps. Jenn ======================== Jenn Riley Metadata Librarian Digital Library Program Indiana University - Bloomington Wells Library W501 (812) 856-5759 www.dlib.indiana.edu Inquiring Librarian blog: www.inquiringlibrarian.blogspot.com
