On Thu, Jan 31, 2013 at 4:18 PM, Magnus Enger <[log in to unmask]> wrote:

The question does raise another interesting problem though: As far as I can tell, moving from MARC to RDF should mean that the concept of the "record" as an island unto itself is dead - the future is built up of descriptions of "things" that are linked to each other, in interesting ways. One challenge might be: If we want to "copy" a description of a "thing", how far should we follow the links it is involved in? When have we harvested enough of the context to have a good description of the "thing"?

The semantics of a bibliographic record are quite subtle.

1. A record does not contain every known assertion about a described thing.
2. There can be many different descriptions of the same thing.  
3. Records may be derived from other records; however, each record is a single set of statements, with a single claimed provenance which applies to every statement in the record. 
4. These descriptions may make statements about objective facts that are inconsistent in such a way that at least one statement must be incorrect (for example, pagination).
5. These descriptions may make statements that are to some degree subjective and where all such statements may be correct (for example, "the main subject of the work"). 
6. Many statements from different descriptions can be combined to give a unified description. 
7. Some descriptions may contain sets of statements that are only correct when taken as a whole, and which, if combined with corresponding statements from a different record, entail results that no creator of any of the records intends or would accept. For example, this can often be the case if FAST headings are used.

A record roughly approximates to a graph in SPARQL where each statement has identical provenance information.  

Simon