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Re: The Ordered List Ontology

From: Bob Ferris <zazi@elbklang.net>
Date: Mon, 28 Jun 2010 13:58:15 +0200
Message-ID: <4C288E57.1010302@elbklang.net>
CC: Linked Data community <public-lod@w3.org>, Semantic Web <semantic-web@w3.org>
Hi Graham,

thanks a lot for this suggestion. I spent some more time in making this 
concept a bit more solid [1,2]. Here the features that I added/changed 
in the v0.3 proposal (+ for added, ~for modified):

  + olo:next - to associate the next slot of a slot in an ordered list
  ~ olo:length - to enable a single length association to an ordered list
  ~ olo:length - rdfs:range xsd:positiveInteger (no empty lists!)
  ~ olo:index - to enable a single index association to a slot in an 
ordered list
  ~ anonymous inverse property of olo:slot to rdfs:type 
owl:FunctionalProperty

With that changes it should be possible

... to create a unique neighbourhood relation; the list ends if the slot 
hasn't a neighbour (that means no is:next property is set)
... to associate a single index to a slot; however, this still not 
prevents from inserting several slots with the same index
... to associate a single length to an ordered list

To model the unique relations for index and length I followed the 
pattern from here[3].

I think, if the size of the ordered list is defined in its length, which 
should be used by a rule for validation, why we need than another 
property, which defines its max length (see also my thoughts about 
practical application)?
I still believe that it isn't possible to guarantee full valid ordered 
lists, without the use of some rules (only with the 
rdf:first/rdf:next/rdf:nil pattern). However, rules are created for some 
purpose, so why not use them (think practical here).
Another practical thought is, if something changes in the ordered list, 
e.g. a new slot would be added, than the graph of the list will be 
rewritten or a new one would be created (that depends on the used 
revision mechanism).

Comments, suggestions, critics on the new proposal are very welcome.

Cheers,


Bob


[1] 
http://motools.svn.sourceforge.net/viewvc/motools/orderedlistsonto/branches/orderedlistsonto_v03/rdf/orderedlistontology.n3
[2] 
http://motools.svn.sourceforge.net/viewvc/motools/orderedlistsonto/branches/orderedlistsonto_v03/gfx/olo_-_orderedlist.gif 

[3] http://www.w3.org/TR/2004/REC-owl-guide-20040210/#simpleCardinality

Am 28.06.2010 10:51, schrieb Graham Klyne:
> Bob,
>
> A desired feature that led to the current rdf:List structure is the
> ability to "close" a list - so some separate sub-graph can't "silently"
> add properties not in the original. Your pattern might allow this
> through additon of a "maxSlotIndex" property on "olo:OrderedList" (not
> suggesting this as a design, just an example).
>
> #g
> --
>
>
> Bob Ferris wrote:
>> Hello everybody,
>>
>> in a longer discussion in the Music Ontology mailing list about how to
>> model a playlist, Samer Abdallah came up with a very good proposal[1]
>> of modelling a sequence/ordered list (as recently also discussed at
>> RDFNext Workshop[2]) as semantic graph (in RDF).
>> So, here we go:
>>
>> - specification[3] (please also note the anonymous inverse properties)
>> - concepts and relations in a graphic[4]
>> - funky playlist example[5,6]
>>
>> Again, thanks a lot Samer Abdallah for that cool concept.
>> Comments, suggestions, critics are very welcome.
>>
>> Cheers,
>>
>>
>> Bob
>>
>> PS: its all OWL based ;) however, we could also downgrade the concept
>> on the basis of rdfs:class, if needed.
>>
>>
>>
>> [1]
>> http://groups.google.com/group/music-ontology-specification-group/msg/305a42362a1e4145
>>
>> [2] http://www.w3.org/2009/12/rdf-ws/slides/rdflist.pdf
>> [3]
>> http://motools.svn.sourceforge.net/viewvc/motools/orderedlistsonto/trunk/rdf/orderedlistontology.n3
>>
>> [4]
>> http://motools.svn.sourceforge.net/viewvc/motools/orderedlistsonto/trunk/gfx/olo_-_orderedlist.gif
>>
>> [5]
>> http://motools.svn.sourceforge.net/viewvc/motools/orderedlistsonto/trunk/examples/orderedlist_-_example.n3
>>
>> [6]
>> http://motools.svn.sourceforge.net/viewvc/motools/orderedlistsonto/trunk/gfx/olo_-_orderedlist_example.gif
>>
>>
>
>


-- 
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Bob Ferris

website: http://elbklang.net
e-mail:  zazi@elbklang.net

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Received on Monday, 28 June 2010 11:58:51 GMT

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