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Re: SPARQL-friendly alternative to rdf:Lists?

From: Hugh Glaser <hg@ecs.soton.ac.uk>
Date: Sat, 12 Oct 2013 12:42:34 +0000
To: semantic-web <semantic-web@w3.org>
Message-ID: <8D9082D7-51EF-4431-ACE8-45D1CAE2A3F1@soton.ac.uk>
An excellent use case is authorship of academic publications.
For some purposes order of authors is important.

This is not a problem in XML etc. but consider the following:
http://eprints.soton.ac.uk/cgi/export/eprint/259084/RDFXML/eps-eprint-259084.rdf (the RDF IR, not the NIR, for convenience).
	uses both containers and simple predicates
	doesn't give ordering
	does it "by hand"

Then ask first how easy it is for a consumer (always!) to ask things like the following:
Names of all the authors;
Name of the prime author;
How many authors;
Names of the co-authors for a given author URI.

But also, how clean is the data - do we really want to encourage multiple representations of the same knowledge?
And a significant question is about how compatible anything is with existing ontologies, such as DC, FOAF and BIBO, which have large existing KBs?

Sorry if this is revisiting old material inappropriately.
On 12 Oct 2013, at 04:45, Axel Polleres <axel@polleres.net>

> FWIW, just to mention that property paths in SPARQL1.1 should have made it a lot easier to query lists in SPARQL.
> Cf. examples at: http://www.w3.org/TR/sparql11-query/#propertypath-examples (also contains an example to query the elements of a list)
> Would that cover your use case? If not, what'd be missing?
> best,
> Axel
> --
> Prof. Dr. Axel Polleres
> Institute for Information Business, WU Vienna
> url: http://www.polleres.net/  twitter: @AxelPolleres
> On Oct 11, 2013, at 4:02 PM, David Booth <david@dbooth.org> wrote:
>> rdf:Lists are notoriously difficult to use in SPARQL if one wishes to retain the *order* of the items in the list.  James Leigh and David Wood made a nice proposal a few years ago to address this problem directly at the RDF level,
>> http://www.w3.org/2009/12/rdf-ws/papers/ws14
>> but for whatever reasons, that work was not included in the charter of the current RDF working group.  As a result people often use some other means of representing ordered lists in RDF, such as by [item, index] pairs.
>> For those who use an alternate way to represent an *ordered* list of items in RDF (instead of rdf:List), I am wondering:
>> 1. What *ordered* list representation do you prefer, and why?
>> 2. Have there been any efforts toward standardizing alternative *ordered* list representations in RDF?  E.g., has anyone written up a spec on how they prefer to do it?
>> Thanks,
>> David
Received on Saturday, 12 October 2013 12:43:11 UTC

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