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Re: XForms Model - XML Schema vs. Simple Syntax - relative importance

From: John J. Barton <John_Barton@hpl.hp.com>
Date: Thu, 15 Feb 2001 09:32:57 -0800
Message-Id: <>
To: <eamon.otuathail@clipcode.com>, <www-forms@w3.org>
At 12:30 PM 2/15/2001 +0000, Eamon O'Tuathail wrote:
> >> I can't imagine using XSLT on a PDA to
> >> convert Simple->Schema:
>I certainly agree with that.
> >> Hmm...can a PDA interpret XML Schema?
>XML Schemas are just text, and XForms browsers could certainly interpret
>them. It is likely in future OSes for PDAs will have XML Schema
>functionality, and if not the XForms browsers implementers can write the
>schema-code themselves. A future XForms-capable browser is also likely to
>include support for SVG, Web3D, SMIL etc., so it is a serious piece of
>software engineering - in this context, writing code to interpret XML
>Schemas is not that great deal.

I'm a bit confused: one the one hand you argue that XSLT is too
hard for PDA; next you say they will have SVG, Web3D, etc.  XSLT is
no more difficult than that lot.

>As the PDA screen size is small, the description of the data (in either
>Simple syntax or XML Schema) is also likely to be small. The Simple Syntax
>will mean fewer bytes need to be transported to the PDA and the PDA can
>interpret it quicker, but how important are these, really? The UI to the PDA
>will most likely contain icons etc. (users don't likely text-only UIs - ask
>the millions of unhappy WAP customers!). Just one PNG file (10s of K in
>size) means the size difference between Simple & Schema (100s of bytes) is
>not important - and if transporting over TCP/IP (not always the case), the
>packet size might mean the size difference is irrelevant.

Do you know of controlled scientific studies that show users "don't like 
text only
UIs"?  I do believe they exist, but I don't believe that the classic studies
from the '80s used small screens.  Moreover, I believe that if icons would
have worked on the current cellphone screens WAP would have icons.  In other
words its not text vs graphics but the extremely small numbers of pixels that
creates the challenge on cellphones.

Anyway the issue here is not UI nor number of bytes sent.  It is whether the
wire format it humanly readable or not.  In my opinion the human readablity
of HTML is the reason we use Webs rather than Orbs.

John J. Barton          email:  John_Barton@hpl.hp.com
MS 1U-17  Hewlett-Packard Labs
1501 Page Mill Road              phone: (650)-236-2888
Palo Alto CA  94304-1126         FAX:   (650)-857-5100
Received on Thursday, 15 February 2001 12:32:54 UTC

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