Ed's / Ian's View

Hi All,

I think Ed and Ian's view can be summarized as follows:

At the abstract level, you make statements about typed resources rather 
than just resources, so rather than saying:

   dc:creator(x, "alice");
   foo:mass(x,2140);

You're actually saying:

   dc:creator(U₁(x), "alice");
   foo:mass(U₂(x), 2140);
   and.. disjoint(U₁(x), U₂(x));

Where U₁ and U₂ are different universes, on the web, and not on the web.

Over the years this has been surfaced in many ways, different examples 
include:

   <x> :accessibleVia "x"              == U₁(x) U₂(x)
   *<x>  foaf:isPrimaryTopicOf <x>     == U₂(x) U₁(x)
   _:x foaf:isPrimaryTopicOf <x>       == U₂(x) U₁(x)
   tdb:x foaf:isPrimaryTopicOf <x>     == U₂(x) U₁(x)

and the inference one (Ed's William Shakespeare example, and as outlined 
above), which is to have the properties specify whether <x> in the 
surface syntax is referring to U₁(x) or U₂(x).

The William Shakespeare example / universe inference approach was 
falling apart when it came to properties like dc:creator on resources 
like wikipedia pages about Books, which to IanD's credit he pointed out, 
and to which Ed responded by effectively saying "well we need a separate 
ontology for talking about things in U₁".

Other cases mentioned (by IanD and others) take the approach of saying 
things like "I'll only use x to refer to things in U₂, not U₁", which 
was later expanded on with the Content-Location suggestion to 
effectively say "I'll only use x to refer to things in U₂, not U₁, and 
if I need to refer to things in U₁ I'll provide some other name for that 
thing" ... but I think it still had the same sentiment of using the 
properties to suggest whether the thing being discussed was in U₁ or U₂, 
for example by saying <x> a :Person, or <x> a :Document but not both.

To me this outlines that:

- there's a kind of distinction being made by people that there are two 
classes of resources, the documents/irs/things on the web, and the 
everything elses. (there are two unvierses)

- that one approach is to use properties to say which universe the x you 
are talking about belongs in ( use x to refer to both U₁(x) and U₂(x) )

- that another approach is to only use x to refer to either U₁(x) or U₂(x)

- that another approach is to use some surface syntax (quotes or *) or 
other form of uri (tdb:) to refer to either U₁(x) U₂(x).

And that currently our solutions are:

- to use absolute iris for things in U₁, and frags for things in U₂
- to use x to refer to things in U₁ and y to refer to things in U₂, 
where 303(x,y)

It's interesting to me though, that it almost every solution (other than 
the infer from properties one) has a build in notion that when you have 
U₁(x) and U₂(x), then U₁(x) provides information about U₂(x), and U₁(x) 
!= U₂(x). Seems to be a running thread there.. even though I know 
strictly speaking that you can say use frag iris to refer to a web 
page.. but I don't see anybody actually doing that.. so maybe people are 
happy with disjoint classes of names, one for things on the web and one 
for things that aren't?

Best,

Nathan

Received on Tuesday, 5 April 2011 16:47:39 UTC