Vocabularies: next steps

[Alasdair Gray]

Hi,

I agree with Rick's suggested 10 commandments except where I've put in a comment below.

Comments preceded by [AG]


-----Original Message-----
From: owner-semantics at eso.org [mailto:owner-semantics at eso.org] On Behalf Of Frederic V. Hessman
Sent: 27 November 2007 11:05
To: IVOA semantics
Subject: Re: Vocabularies: next steps

[AG] [snip]

1. A single SKOS document defines the vocabulary and must be  
publically available at some URI, preferably
	at the central IVOA vocabulary repository http://www.ivoa.net/?????  
at least as a copy.

[AG] Should probably say something about the SKOS document being well formed. This should probably include the use of language labels for preferred and alternate labels.

2. A concept token has the form

			{URI-root}{vocabulary-name}#{token}

	where the token should consist only of the letters a-z, A-Z, and the  
numbers 0-9.  The URI root and vocabulary
	name should be set centrally and not in the definition of each  
token.  For example, if a nominal concept is

			http://www.ivoa.net/Thesauri/Food#Apple

	(root="http://www.ivoa.net/Thesauri/", name="Food", token="Apple"),  
then the SKOS definition begins with

			<skos:Concept rdf:about="#Apple">

3. One is encouraged to use human-readable forms for the tokens with  
some obivous connection to
	the preferred labels, e.g. conversion from the label via dropping  
characters not included in the
	above list and sub-token separation via capitalization (e.g. "My  
favorite idea-label #42" ->
	"MyFavoriteIdeaLabel42")

4. Vocabulary entries should be singular unless based on previously  
determined sources where the
	conversion to singular forms would impare the usefulness of the  
vocabulary.

5. Thesaurus entries (BT/NT/RT) are encouraged but not required.

6. If thesaurus entries are included, they should be complete (all BT  
links are reflected in corresponding
	NT links in the referenced entries).

[AG] Likewise all RT are symmetrical.

7. "TopConcept" entries should normally be those not  having a BT  
reference but the maintainers of
	a  vocabulary can decide to restrict the choice of TopConcepts if  
appropriate.

8. Use of standard SKOS documentation is encouraged but not required:  
e.g.

	scopeNote		to clarify usage
	historyNote		to identify when the vocabulary entry was created
	changeNote		to identify changes in already created entries

9. The maintainers of a vocabulary should provide on-line  
documentation permitting the easy perusal of labels
	and any thesaurus and usage information.  The IVOA will try to  
maintain a list of links to known vocabularies
	and may choose to provide it's own consistent on-line documentation  
based on the SKOS files alone.

[AG] I do not see this as a pre-requisite. All that is needed is the SKOS file. These can be plugged into various tools that are coming on-line to enable the browsing. For example, there is a protégé plugin in the process of being tested and I am in the process of developing a web service for exploring skos vocabularies.

10. The maintainers of a vocabulary should attempt to cross-reference  
their vocabulary with one or more IVOA
	supported vocabularies, e.g. UCD1 and/or IVOAT.

[AG] Again, I do not see this as a pre-requisite. Others are equally well suited to declare their own mappings between vocabularies.

Anything else?  Having just Ten Commandments would be nice.

[AG] So perhaps 9. Should be the use of language labels in preferred and alternate labels and I don't have a suggestion for 10 right the now.

[AG] [snip]

[AG] Cheers,


[AG] Alasdair


Alasdair J G Gray
Research Associate: Explicator Project
http://explicator.dcs.gla.ac.uk
Computer Science, University of Glasgow
0141 330 6292