Phil Dawes' Stuff - Latest Comments in Global identifier schemes don't scale

Re: Global identifier schemes don't scale

Nat — Thu, 09 Mar 2006 06:57:42 -0000

The security community have been thinking about these issues for some time. Here's that overview of global names vs. nicknames vs. pet names I mentioned at XTC.

http://www.skyhunter.com/marcs/petnames/IntroPe...

Re: Global identifier schemes don't scale

Phil Dawes — Thu, 09 Mar 2006 03:54:18 -0000

Hi Matt,

Sure - I agree that this is a better way of factoring the semantics, but my point is that I didn't write this. By leaving out the date I effectively lumped the time and other state variables (such as whether id:PhilDawes is wearing clothes) into the pool of ambiguity around the identifier.
This ambiguity makes it easy for others to use the same identifier inconsistently - not necessarily inconsistently with the original document, but inconsistently with each others interpretations. (It's a practical issue rather than a theoretical one).

The upshot is that you need to consider the context of the communication to determine what is actually being identified.

Re: Global identifier schemes don't scale

Matt — Wed, 08 Mar 2006 10:07:26 -0000

That'll teach me to use angle brackets in text.

id::PhilDawes (weight 10st, date 24/12/2005)
id::PhilDawes (weight 10st 3lbs, date 26/12/2005)

Re: Global identifier schemes don't scale

Matt — Wed, 08 Mar 2006 10:05:50 -0000

Hang on, the problem is that your example data changes over time, not with the global identifier. If you write:
id::PhilDawes
id::PhilDawes
then you have two data items about the same uniquely identified PhilDawes. They're not statements about an object at different times, they're statements (which happen to have a time component) about the same timeless object.

Re: Global identifier schemes don't scale

Seth Russell — Tue, 07 Mar 2006 14:18:45 -0000

I think your on to something here :) Any identifier, and i don't care how global it is in scope, gets its meaning from the context of it's use. That's why the triple was a bad choice for the Semantic Web. You will get better results by including a context identifier with the assertion. Check out my suggestion for Quads.