[TagCommons-WG] mechanisms for sharing tag data

[Richard Newman]

On  1 Mar 2007, at 5:31 PM, Nitin Borwankar wrote:

> I am wary of acccepting a single database schema at this stage ( even
> though I think the ones suggested at tagschema.com are quite  
> useful ;-)
> ) or a single ontology.
> Let's instead agree on common  *interfaces* without, at this stage,
> insisting on one common internal representation or the other.

Nitin,
   I think you're misunderstanding the word 'ontology' in this  
context. An ontology describes the conceptual model of a domain, a  
model that an interface programmatically encodes. The idea of an  
interface that doesn't commit to a single ontological model is  
nonsensical.

   Of course, the choice of URIs in a particular RDF encoding of such  
an ontology is a different matter, but the ontology itself  
necessitates quite a firm contractual commitment from a participant.  
For example, that a tagging event is some kind of relation between a  
tagging party, a tagged resource, and a tag is a core part of such an  
ontology.

> So from my view point we should start at the outside - a REST  
> interface
> and work our way in.
> A REST interface would need a set of operations and a format for
> returned data.
> Once we agree on what the "fine structure" of  a tag is or at least  
> what
> part of it we can agree upon, then lightweight data structures  
> expressed
> in YAML ( or JSON ) fall out of that.  So we would have to work at the
> "intersection" of our respective models, first.

I think the opposite: that a consistent, sensible data model easily  
lends itself to defining consistent interfaces and data models that  
commit to the same ontological contracts.

> This would encourage data providers to expose their data in compliance
> with the "TagCommons REST API and formats" and data consumers that  
> write
> apps
> to use it, without all of us *first* having to agree on database  
> schemas
> or ontologies.  That agreement may never happen or need to happen and
> those conversations
> can sometimes go on for ever or quickly become closed conversations.

I think that the difference in our viewpoints comes from a difference  
in our definitions of "ontology".