Hi Rob,

do I understand it correctly? Instead of

<w> a Work ;
  bf:issn <i> .

<i> a Identifier ;
  rdf:value "1234567890" .

we should better think about something like this?

<w> a Work ;
  bf:identifier <i> .

<i> a ISSNIdentifier ;
  rdf:value "1234567890" .

I'd prefer the latter, instead of inflating Bibframe with concrete identifier properties like bf:issn, bf:isbn etc. there is just a common bf:identifier property.

(Not only for bf identifiers, this construction can be generalized).

Jörg


On Sat, Nov 8, 2014 at 2:32 AM, Robert Sanderson <[log in to unmask]> wrote:

<w> a Work ;
  bf:issn <i> .

<i> a Identifier ;
  rdf:value "1234567890" .

If I dereference <i>, I have no idea that the resource is an ISSN.

Thus we need to include that information associated with the resource.  That leads to identifierScheme ... which is a URI.
So now we have:

<i> a Identifier ;
  scheme <http://.../issn/> ;
  value "1234567890" .

But an ISSN is a *type* of Identifier, and redundant with the class bf:Identifier.  There can be no resource which has a scheme of <issn> which is not an Issn Identifier.

Thus we simplify the model to:

<i> a IssnIdentifier ;
  value "1234567890" .

QED?