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Re: Biological Taxonomy Vocabulary 0.1

From: Dan Brickley <danbri@danbri.org>
Date: Sat, 10 May 2008 18:34:56 +0100
Message-ID: <4825DCC0.4000200@danbri.org>
To: Richard Cyganiak <richard@cyganiak.de>
Cc: Toby Inkster <tai@g5n.co.uk>, rdf-schema-dev@googlegroups.com, Renato Golin <renato@ebi.ac.uk>, public-rdf-in-xhtml-tf@w3.org, Semantic Web <semantic-web@w3.org>

Richard Cyganiak wrote:
> 
> Toby,
> 
> [CC'ing rdf-schema-dev]
> 
> This is very interesting, and it's nice to have an example of an RDF 
> vocabulary that is defined using RDFa. It's obvious that a lot of work 
> and care went into preparing the HTML+RDFa document. Very well done!
> 
> Some specific comments below.
> 
> 1. Your RDFa contains an owl:Ontology instance. You made it a blank 
> node. It should be http://purl.org/NET/biol/0.1 instead, because that's 
> the URI of the ontology.
> 
> 2. I think the version numbers in the URIs are a bad idea. FOAF has 
> changed quite massively over the last years, and it's still at 0.1, 
> because actually changing the version number would break all existing 
> clients. Dan Brickley has stated that it will always remain at 0.1. And 
> unlike the complex area of describing people and their social 
> relationships on the ever-shifting Web, your subject matter is rather 
> stable and well-defined, so version numbers seem even less useful in 
> your domain. (If you should ever decide to design a completely different 
> and entirely incompatible vocabulary, just call it something else 
> instead of fiddling with version numbers.)

Yes, please find different mistakes to make instead of copying mine ;)

What happened with FOAF: it just kept growing from the initial spring 
2000 proof of concept and there never seemed a right time to cut over to 
a "better" namespace URI.

In general, updating a vocab in place is something that makes a lot of 
sense. Embedding status metadata within the namespace URI is somewhat in 
conflict with this approach. Fairly early in FOAF we started using 
per-term annotations instead, so that we could call 'foaf:name' a stable 
property, and 'foaf:dnaChecksum' an unstable property, without coupling 
that rigidly to the namespace URI. Changing namespace URIs is the most 
enormous pain; I don't recommend anyone does so casually. Changing 
annotations is rather easier.

BTW, I don't consider FOAF to be "at version 0.1"; rather, the FOAF 
namespace happens to contain the string "0.1". Think of it as 1.0 
backwards...? The namespace also contains the string ".com", but it is 
not a commercial venture. And the string 'xml', although it can be 
implemented without (much) use of XML.

For these reasons I've recently redirected the main public spec URI to 
be http://xmlns.com/foaf/spec/

The latest version is
	FOAF Vocabulary Specification 0.91
	Namespace Document 2 November 2007 - OpenID Edition

..even though the namespace URI continues stubbornly to have 0.1 in it.

cheers,

Dan

--
http://danbri.org/
Received on Saturday, 10 May 2008 17:35:41 GMT

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