[Proposal][SKOS-Core] Notes

Here's my first draft of a proposal (See also requirements for notes linked from 
[1]):

We employ a property hierarchy, which can be extended by scheme owners via 
rdfs:subPropertyOf for more specific note properties.

Below is the property hierarchy I suggest:

rdfs:comment	
	skos:publicNote
		skos:definition
		skos:scopeNote
		skos:example
		skos:historyNote
	skos:privateNote
		skos:editorNote

... with the following definitions (and comments):

skos:publicNote
  - A note intended for public consumption.
  - (This property not intended to be used directly, but as a super-property for 
other properties indicating documentation intended for public consumption.)

skos:definition
  - A statement or formal explanation of the meaning of a concept.

skos:scopeNote
  - A note that helps to clarify the meaning of a concept.
  - (Typically used to describe what is or is not in scope for the concept, i.e. 
what is or is not included in the concept's meaning.)

skos:example
  - A note or resource that illustrates the intended use of a concept.

skos:historyNote
  - A note about the history or past use and meaning of a concept.

skos:privateNote
  - A note not intended for public consumption.
  - (This property not intended to be used directly, but as a super-property for 
other properties indicating documentation not intended for public consumption.)

skos:editorNote
  - A note for an editor, translator or maintainer of the vocabulary.

----

I also suggest three optional modes of usage for these properties:

  - Mode 1 (Literal): the value of the property is a Literal (useful where 
scheme owner wants to keep things as simple as possible).

e.g.

<skos:Concept rdf:about="http://example.org/topics/0304">
	<skos:definition xml:lang="en">Any of several treelike Asian herbs of the genus 
Musa, especially M. acuminata, having a terminal crown of large, entire leaves 
and a hanging cluster of fruits.</skos:definition>
</skos:Concept>

  - Mode 2 (Blank node resource): the value of the property is a blank node, 
with the text of the note being placed as the value of an rdf:value property of 
the blank node (useful where additional information about the note must be 
represented, e.g. author or date).

e.g.

<skos:Concept rdf:about="http://example.org/topics/0304">
	<skos:historyNote rdf:parseType="Resource">
		<rdf:value>The definition was modified to include members of the plantain 
family.</rdf:value>
		<dc:date>2004-08-02</dc:date>
	</skos:historyNote>
</skos:Concept>

  - Mode 3 (Resource): the value of the property is a textual web resource (such 
as html or text file) containing the body of the note (useful where e.g. example 
    or definition exists in separate file).

e.g.

<skos:Concept rdf:about="http://example.org/topics/0304">
	<skos:example>
		<rdf:Description rdf:about="http:example.org/examples/0304.html">
			<!-- additional properties of the file could also be mentioned here, e.g. 
author. -->
		</rdf:Description>
	</skos:example>
</skos:Concept>

Having three different modes of usage shouldn't be a problem, because 
applications will be able to detect the difference easily (i.e. is the statement 
object a Literal? Yes -> Mode 1, No -> Is the value a blank node? Yes -> Mode 2, 
No -> Mode 3.

Comments on any part of this proposal?

Al.




-- 
Alistair Miles
Research Associate
CCLRC - Rutherford Appleton Laboratory
Building R1 Room 1.60
Fermi Avenue
Chilton
Didcot
Oxfordshire OX11 0QX
United Kingdom
Email: a.j.miles@rl.ac.uk
Tel: +44 (0)1235 445440