Now you might be thinking that we've just written a schema describing those cute furry creatures that whistle and toot when you stroke them. Sadly no. FRBR stands for Functional Requirements for Bibliographic Records and is a report issued by the International Federation of Library Associations and Institutions. It describes a high level conceptual model of creative works and how they are represented in the real world. Bet you wish we had done the furry alien thing.
In the library and cataloguing world, FRBR is a big deal. It standardises a set of terms and relationships that are essential to any cataloguer. The central concept is that of the Work which is a distinct intellectual or atistic creation. A work is an abstract notion and is completely intangible. You can talk about a work but you can't physically touch it. When someone conceives of a new work they typically try to express its ideas in some way. A composer might have the notion of a musical composition in mind, and they could express it by writing notes on a stave, humming into a microphone or playing it on a piano. These are Expressions, another core concept in FRBR. A Work is realized through Expressions. An Expression comprises the specific words, symbols or notes that are used to express the Work. Sometimes the same Work is expressed in different words, think of all the different variations of the story of Rumpelstiltskin that you might have read. These are all different Expressions of the same Work. An Expression is usually published and may have several different but related editions. These are called Manifestations. Whenever a particular Expression of a Work is reprinted or reissued without materially changing its content, then it becomes a new Manifestation. The final core concept of FRBR is that of the Item. An Item is an actual physical copy of a particular Manifestation. That Shrek DVD on my shelf is a different physical Item to the one on your shelf, but they are both examples of a specific Manifestation - they look identical when we compare them but they are physically distinct.
That's not all there is to FRBR, it also describes people, places, objects and events, but these take a supporting role for the central concepts of Work, Expression, Manifestation and Item. The FRBR report is freely available and quite readable. Our RDF expression of that work is less readable at the moment - it has very little prose and a lot of raw data - but we're working on it and we'd love to have feedback on all aspects of it.
Here are some examples that I've come up with based on my understanding of FRBR that might help:
Lord of the Rings is a Work conceived by J.R.R. Tolkien. The primary Expression of that Work is the book that he wrote. This had several Manifestations - the original publication, a single volume edition, multiple reprints. I have a tattered copy in my book collection - this is one Item. A different Expression of the same Work is the screenplay co-written by Peter Jackson. This had several Manifestations - scripts for the actors, production instructions etc. The films themselves were further Expressions of the same Work. The theatre version and the extended versions were different Expressions with their own Manifestations onto VHS and DVD. I have several of these Items on my shelf.
This one I'm less sure about but I think it could be significant. In the Web Architecture what we call a Resource, FRBR would call a Work. Each Representation of that Resource is an Expression of that Work. In other words the HTML and XML versions of a particular page are different Expressions of that page. When a Web browser requests a particular Expression it gets a snapshot of it at a point in time, this is a Manifestation. The Web Architecture doesn't name this explicitly but it is implicit in some of the HTTP negotiation that goes on around character sets and ranges. The actual bytes that are transmitted and end up on my hard disk are the Item relating to this Manifestation.
This is why I'm pretty excited to have the opportunity to work on something like FRBR. I think it's going to be a core referent for many other schemas and will enable a base level of common vocabulary between disparate systems. I want to see MusicBrainz, AudioScrobbler, IMDB, Creative Commons, Amazon and so many others using it to describe their catalogues and metadata in a feely interchangeable fashion!
Finally, if you managed to get through all that, treat yourself to some pictures of cute furry aliens. All together now, ahhhhh.