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Re: Ordering concepts in a Tree display

From: Antoine Isaac <aisaac@few.vu.nl>
Date: Tue, 18 Jan 2011 17:54:47 +0100
Message-ID: <4D35C5D7.2060504@few.vu.nl>
To: Christophe Dupriez <christophe.dupriez@destin.be>
CC: Jakob Voss <jakob.voss@gbv.de>, SKOS <public-esw-thes@w3.org>
Hi Christophe,

My two cents: (2) will be difficult to use in KOSs where a concept can have several parents, wouldn't it?
(1) somehow makes sense, even though it is not practical. But I'd like to remind what Jakob said: "using ordering in RDF is a pain in the a**". That applies to any pattern you could dream of for your RDF data--in fact it also applies to the discussion on representing (pre)coordinated concepts, which landed on that list last week. There's no free lunch, here, truly! In fact your solution (3) with the reification of the broader or narrower statement would more complex, but not much so: in both case you would have to pay a quite high price for your tool to access the relevant data :-/

Antoine


> Thanks for the information!
>
> What is the most natural:
> (1) post-ordering concepts in lists (orderedCollection)
> (2) "pre" ordering concepts by assigning them a number (for instance begining year for an era, school years for a student grade, number of wheels for a vehicle, etc.)
> I used method (2) for decades before advent of SKOS.
>
> Does (1) makes sense for this use?
> * it introduces a new object in the file (the orderedCollections) that must be managed somehow/somewhere.
> * how the displaying program knows that the NT concepts must be presented following the orderedCollection?
> It is the NTs which are listed, not the orderedCollection!
> (and worse: the concept could be in multiple orderedCollections for different purposes than display ordering)
> * A previous message proposed to make collections of collections instead of using NTs/BTs. Not very practical for general thesauri:
> http://lists.w3.org/Archives/Public/public-esw-thes/2009Mar/0000.html
>
> With (2), you just add a "rank" property to the concept...
>
> (3) the real "perfect" solution, is to have a rank within the BT/NT relation. I suppose no one wants to reify the SKOS relations!
>
> For now, I will create a namespace for a ranking property...
>
> Have a nice w.e.!
>
> Christophe
>
> Le 14/01/2011 13:15, Jakob Voss a écrit :
>> Hi Christophe,
>>
>>> Does anyone have designed a way to specify concept ordering when
>>> displaying a tree of concepts?
>>
>> To ensure *any* ordering, the concept scheme must be encoded with
>> http://www.w3.org/TR/skos-reference/#collections
>>
>>> Usually, alphabetical ordering is the best to display narrower concepts
>>> of a given concept.
>>
>> You could also order by number first displaying NTs that have other NRs followed by leafs, or you could order by number of documents, indexed with the concepts, or by skos:notation (if given) etc.
>>
>> But sure, the most common way of sorting is alphabetical - which depends on the language, by the way! I would always assume, that there is no natural order of elements in RDF data unless it is explicitly stated. But using ordering in RDF is a pain in the a**: In most cases you first need to in infer some entailment and do validity checks on the lists. Otherwise your ordering could turn out to be a tree or to have circles!
>>
>> Cheers
>> Jakob
>>
>
>
Received on Tuesday, 18 January 2011 19:45:11 UTC

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