- From: pat hayes <phayes@ai.uwf.edu>
- Date: Tue, 14 Aug 2001 12:21:25 -0700
- To: Patrick.Stickler@nokia.com
- Cc: www-rdf-logic@w3.org
> >Well, I'm probably going to get grilled for this comment, but personally >I don't like anonymous nodes. After all, just what *is* an anonymous >node. Every application that I've seen that uses them has had to give >them some form of identity, and yet that identity is system dependent. The NODE has an identity, but it doesnt have a label which denotes anything. The easiest way to understand anonymous nodes is just like existentially quantified variables in logic, ie they assert that something exists (just like a name or a URI does) but they don't give it a name (unlike a name or a URI). That is widely considered to be a handy thing to be able to do, and it is well-defined and seems harmless, so why not allow it? >IMO, anonymous nodes were a hack to allow collection structures as Objects, >but yet collections (or rather ordered collections) in RDF do not work in >an context of multi-source syndication (nor do DAML collections either). >The proper way IMO to model collections is using an ontology of collection >relations and plain old triples with no anonymous nodes; but that's a >separate >discussion that I don't want to start here. Nothing would be greatly changed if all anonymous nodes were made non-anonymous, but there would be a lot of silly names cluttering up things to no useful purpose. >Issues of completeness required by the closed world folks can be addressed >by assigning source or authority to statements so that one can selectively >filter those collection members defined in a particular source or by >a particular authority and "outsiders" cannot add to that "view" of the >collection. IMO, the RDF conceptual model should have no anonymous nodes. >Collections based on serialized, syntactic structures should have no >realization in the underlying conceptual model; but again, that's yet >another discussion ;-) That is certainly another point of view about collections, but there are other reasons for allowing anonymous nodes. >I will concede that there *might* be valid and necessary uses for anonymous >nodes which I am not yet aware of, but irregardless I get the impression >(and I may very well be wrong, apologies in advance) that anonymous >nodes are the new, "hot", interesting thing in RDF/DAML and so folks are >predisposed to using them to solve every problem even when more >constrained, simplier, and better alternatives may be available. > >For those who are convinced that anonymous nodes are a good thing, please >think about the implementational burden and portability/interoperability >issues they may introduce. What burdens and issues? . Pat Hayes --------------------------------------------------------------------- (650)859 6569 w (650)494 3973 h (until September) phayes@ai.uwf.edu http://www.coginst.uwf.edu/~phayes
Received on Tuesday, 14 August 2001 15:20:51 UTC