RE: Are we losing out because of grammars? (Re: Schema ambiguitydetection algorithm for RELAX (1/4))

["Bullard, Claude L (Len)" <clbullar@ingr.com>]

Precisely.   What that says to me is that 
we have to know the bounds of the system 
to determine the requirements for the 
means of valdiation, which is why I suggest a 
broadcast model at the high end.   

So we are back to Shannon's H and K values.  
We have to determine a measure for the 
granularity of the unit of information (K) and 
the means to determine the uncertainty (H) 
for any value of K.  Sounds theoretical but, IMO, 
is the practical problem in a nutshell.

Len 
http://www.mp3.com/LenBullard

Ekam sat.h, Vipraah bahudhaa vadanti.
Daamyata. Datta. Dayadhvam.h


-----Original Message-----
From: Rick Jelliffe [mailto:ricko@allette.com.au]

I think there are two kinds of schemas and therefore schema languages: one
tries to express what is true of all data of that type at all times (e.g.
for storage and 80/20 requirements) and another tries to express the things
that make that particular information at that particular time and context
different from other data of the same type.  One tries to abstract away
invariants, the other tries to find abstractions to express these
variations.

The first kind is a map, the second kind is a route.  The first kind is good
for automatically generating interfaces and for coarse validation, the
second kind is what is required for data-entry and debugging all data at
all. (As for the status quo, I don't believe XML Schemas and DTDs pay much
or any attention to this second kind of schema: maybe TREX and RELAX do a
little bit and I hope Schematron is closer to the other end of the
spectrum. )