- From: Harry Halpin <hhalpin@ibiblio.org>
- Date: Thu, 1 Jul 2010 00:24:02 +0100
- To: Pat Hayes <phayes@ihmc.us>
- Cc: Dan Brickley <danbri@danbri.org>, Toby Inkster <tai@g5n.co.uk>, Graham Klyne <GK@ninebynine.net>, Bob Ferris <zazi@elbklang.net>, Linked Data community <public-lod@w3.org>, Semantic Web <semantic-web@w3.org>
On Wed, Jun 30, 2010 at 8:17 PM, Pat Hayes <phayes@ihmc.us> wrote: > > On Jun 30, 2010, at 1:15 PM, Dan Brickley wrote: > >> On Wed, Jun 30, 2010 at 6:34 PM, Pat Hayes <phayes@ihmc.us> wrote: >>> >>> On Jun 30, 2010, at 6:45 AM, Toby Inkster wrote: >>> >>>> On Wed, 30 Jun 2010 10:54:20 +0100 >>>> Dan Brickley <danbri@danbri.org> wrote: >>>> >>>>> That said, i'm sure sameAs and differentIndividual (or however it is >>>>> called) claims could probably make a mess, if added or removed... >>>> >>>> You can create some pretty awesome messes even without OWL: >>>> >>>> # An rdf:List that loops around... >>>> >>>> <#mylist> a rdf:List ; >>>> rdf:first <#Alice> ; >>>> rdf:next <#mylist> . >>>> >>>> # A looping, branching mess... >>>> >>>> <#anotherlist> a rdf:List ; >>>> rdf:first <#anotherlist> ; >>>> rdf:next <#anotherlist> . >>>> >>> >>> They might be messy, but they are *possible* structures using pointers, >>> which is what the RDF vocabulary describes. Its just about impossible to >>> guarantee that messes can't happen when all you are doing is describing >>> structures in an open-world setting. But I think the cure is to stop >>> thinking that possible-messes are a problem to be solved. So, there is >>> dung >>> in the road. Walk round it. >> >> Yes. >> >> So this is a point that probably needs careful presentation to new >> users of this technology. Educating people that they shouldn't believe >> any random RDF they find in the Web, ... now that is pretty easy. >> Still needs doing, but it shadows real world intuitions pretty well. >> >> If in real life you think the Daily Mail is full of nonsense, then it >> isn't a huge leap to treat RDFized representations of their claims >> with similar skepticism (eg. see >> http://data.totl.net/cancer_causes.rdf for a great list of Things The >> Daily Mail Say Might Cause Cancer). >> >> *However* it is going to be tough to persuade developers to treat a >> basic data structure like List in the same way. > > Sure. But what they need to grok is that RDF does not have ANY data > structures in it (except maybe triples). It describes data structures, just > like it describes everything else. It does not PROVIDE data structures. > Maybe it should - make the case! - but then it will need to change rather > drastically in its very foundation. Triples describing lists are not the > same as triples-plus-lists. The issue is here that RDF started as a metadata format to "describe" data I believe, and at this point with the Linked Data is now being transformed into a generic language *for* data, period. The lack of lists (and hashes, and other things programmers are used to dealing with) in a reasonable (read "non-XML") syntax is one of the primary reasons the developer community has moved towards JSON. Now, the question is "Would it be possible to provide a JSON-like number of data-structures in RDF, and what would this do to its semantics?" Pat? Given that programming langauge semantics define these things all the time and it's pretty standard, I imagine its possible. But it might make life hard for the principles that RDF was founded upon, i.e. the sort of "open world" flavor of it all. Thus, I imagine it's a trade-off, like most good things in life :) > > Pat > >> Lists are the kinds of >> thing we expect to be communicated perfectly or to get some low-level >> error. A lot of developers will write RDF-consuming code that won't >> anticipate errors. Hopefully supporting software libraries can take >> some of the strain here... >> >> cheers, >> >> Dan >> >> > > ------------------------------------------------------------ > IHMC (850)434 8903 or (650)494 3973 > 40 South Alcaniz St. (850)202 4416 office > Pensacola (850)202 4440 fax > FL 32502 (850)291 0667 mobile > phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes > > > > > > >
Received on Wednesday, 30 June 2010 23:24:32 UTC