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Re: patterns vs. identifiers

• To: Mike Champion <mc@x...>, xml-dev@l...
• Subject: Re: patterns vs. identifiers
• From: Paul Prescod <paul@p...>
• Date: Tue, 20 Aug 2002 08:30:47 -0700
• References: <VSJHWRXT1TMGD0YXGADB716584US04.3d625126@MChamp>

Mike Champion wrote:
> 
>...
> 
> Perhaps RDF can be used as a pattern-matching tool rather than
> a logical inferencing system, and maybe "pattern matching" can be logical
> as well as heuristic. Still, an astronomical number of electrons
> have changed state in search of a definition of URIs that can
> support the needs of RDF, and that suggests to me that the notion
> of "identity" is profoundly important in the RDF paradigm.

RDF exists to solve a problem: associating metadata with web objects.
You can't do that without a strong notion of identity.

>...
> All that puts a lot of "fuzz" in the system ... Which version of the
> spec does this URI refer to?  What happens if it validates with the
> sender's schema processor but not the reciever's?  What happens if the
> "real" URI is http://www.w3.org/some/thing/or/another but the webmaster
> "nicely" set things up so that http://www.w3c.org/some/thing/or/another
> is an alias, so the URI checking logic breaks?

IMO, RDF tools have more ability to handle these problems than do XML
tools.

> My point is that when humans are involved, there are a bazillion ways for
> identities to break, and if a system's logic depends entirely on the identities
> being correct, it will be fragile.  

I agree. You rename "H1" to "Q1" and almost every XHTML tool in the
world will break. But somehow we manage. ;)

> ... If the logic depends on webs of identity
> in metadata, it will probably be even more fragile because (up to now, anyway)
> metadata tends to be "metacrap" because it is of less value to the authors,
> or less visible in the tools, or whatever.

There are megabytes of explicit, machine-readable metadata floating
around the Web every day in the form of RSS files, HTML titles, MIME
headers (including "subject" lines and "cc" lines), the ODP and so
forth.

> ... My argument is that an approach that is more
> ambiguity tolerant, based on patterns in data rather than identity defined
> by metadata, can be an attractive alternative when there are fallible humans
> around to screw things up.

Sure. But how does this set up a dichotomy between "identifiers" and
"patterns"? Identifiers and patterns are just orthogonal tools that are
usually used together!
-- 
"When I walk on the floor for the final execution, I'll wear a denim 
suit. I'll walk in there like Willie Nelson, John Wayne, Will Smith 
-- Men in Black -- James Brown. Maybe do a Michael Jackson moonwalk."
Congressman James Traficant.

• Follow-Ups:
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    • From: Uche Ogbuji <uche.ogbuji@f...>

• References:
  • Re: patterns vs. identifiers
    • From: Mike Champion <mc@x...>

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