Re: what's wrong with using XML Schema/HTML/RDF to document namespaces?

Dan Connolly wrote:
> On Tue, 2002-12-10 at 00:46, Tim Bray wrote:
>> An XML Schema is highly architecturally unsound because it is (a) by 
>> default not human readable,
> Hmm... it seems to be as human readable as, say, an SVG document,
> or even HTML; if you have schema visualization tools, you can
> make sense of it. If not, you can follow-your-nose to
> natural langauge documents that explain, to the satisfaction
> of a wide technical audience, what it means.

A schema doesn't provide much interesting information to a human being as to 
what the vocabulary is for, just information on constraints (and perhaps typing) 
relating to its instances.

>>(c) suggests 
>>that schemas are more interesting or useful than other kinds of 
> In the 2000/04schema-hacking/my case, yes; as namespace designer,
> I've decided that the most useful thing to use to document it is an
> XML Schema.
> Are you saying that's *never* the case?

No, but it does make it so that for a given namespace URI, you only retrieve a 
single type of resource. One may need a schema (or several), a few stylesheets, 
some human documentation... The only way to get all that without RDDL is to use 
content negotiation and try all types that you possibly wish to retrieve. I 
don't find that very practical.

>>and (d) has no default way to look up other useful things 
>>that aren't XML schemas. 
> Yes, it does: annotations; specifically, the source
> attribute on appinfo and documentation.

That only works if you know how to process a schema.

In other words, it's wrong because it's not interoperable. It's also wrong 
because we want to have our cake and eat it too, and by ensuring RDDL instead of 
something else, we can.

Robin Berjon <>
Research Engineer, Expway
7FC0 6F5F D864 EFB8 08CE  8E74 58E6 D5DB 4889 2488

Received on Wednesday, 11 December 2002 13:06:48 UTC