> From: Dublin Core Social Tagging 
> [mailto:[log in to unmask]] On Behalf Of Pete Johnston
> Sent: 03 November, 2006 06:27
> To: [log in to unmask]
> Subject: Re: [DC-SOCIAL-TAGGING] The "social" in social 
> tagging (Was RE: Welcome!)

> I think we need to be careful not to confuse two very 
> different types of thing, two different types of term used in 
> DC metadata: properties and vocabulary encoding schemes.
> ...
> It's the property 
> which specifies the nature of the relationship, and as long 
> as I'm using the dc:subject property, I'm asserting a 
> "has-topic"/"is-about" relationship.

I agree that we need to be careful, especially when, as you
suggest, tags are not necessarily "about" something.  The
unfortunate part is that people and systems are lumping tags 
into dc:subject.  So I think a valid question to ask is: do 
you want to relax the semantics for dc:subject?

> And in my previous message, I was arguing that when people "tag"
> resources, yes, they are asserting a relationship between the 
> tagged resource and a tag (but see also note below), but it 
> is _not_ true that the relationship they are asserting is 
> always a "has-topic"/"is-about"
> relationship. On the contrary, people use tagging to 
> represent all sorts of relationships  - ownership, status, 
> "rating", related-location.
> ...
> You could argue 
> that the dc:relation property does the job - there is some 
> unspecified type of relationship between the resource  and 
> the tag - or you could argue for a more specific 
> "is-associated-with-tag" or "is-tagged-with" property.
> I'd argue against putting "subject" in the name/URI because I 
> think we want to avoid suggesting (even to a human reader) 
> any relationship with the dc:subject property.

To summarize your argument about tags:
1) Tags are sometimes used to indicate identity.
2) Tags are sometimes used to indicate genre.
3) Tags are sometimes used to indicate aboutness.
4) Tags are sometimes used to indicate relationships.
5) dc:relation more appropriately models tags than dc:subject

What I find interesting about this summary is that in DC,
identity is expressed by dc:identifier, genre is expressed
by dc:type, aboutness is expressed by dc:subject and 
relationships are expressed by dc:relation.

I'll put forth the following intellectual argument.  Perhaps 
the DCMI Abstract Model incorrectly models dc:identifier, 
dc:type and dc:subject.

Given your position, one could argue that dc:identifier really
specifies a specific relationship to the resource, e.g., identity
where the content is a handle or "tag".  The same being true for 
dc:type and dc:subject.  You could argue that the model should 
look something like:

dc:relation
  *:tag
    dc:identifier
    dc:type
    dc:subject

* some unknown namespace

where dc:subject is-a class of *:tag, dc:type is-a class of *:tag,
dc:identifier is-a class of *:tag, and *:tag is-a class of
dc:relation.

This Heretic Abstract Model (HAM :) doesn't change the semantics
for dc:identifier, dc:type or dc:subject.  They just indicate
classes of *:tag whose semantics are identity, genre/form and
aboutness.  In addition, HAM's *:tag could be used as a broad
class in social tagging system allowing them to define their
own special types in a similar manner to the strategy I
mentioned for defining new VES (Vocabulary Encoding Schemes).


Andy.