DIA trip report
Author: Jacco van Ossenbruggen

 W3C Workshop on Web Device Independent Authoring (DIA)
 Tuesday/Wednesday, 3/4 October 2000
 HP Labs, Bristol, OK
 http://www.w3.org/2000/10/DIAWorkshop/

While the workshop participants all had pretty diverse backgrounds, I
think you could roughly distinguish:

 - W3C incrowd (Daniel Dardailler, Dave Raggett etc)
 - Accessibility  (WAI WG, etc)
 - Mobile phone (Erikson, Nokia, phone.com, etc)
 - Miscellaneous (including interactive TV, UIML, multimedia, etc)

Despite this diversity, there was consensus about the need for a W3C
activity on DIA, and to a certain extent there also was consensus
about the direction this should go.  This included making guidelines
about how to use the current specs in a way that optimizes device
independence; similar to the WAI guidelines for accessibility.  It
also included cross-working group activity to coordinate the various
standardization efforts, and some empirical study (a la the former web
characterization activity) to investigate the current state of the art
on DIA: what and how do people currently do it and what else is
needed.

The main purpose of my talk was to get rid of the assumption that
device independence is only an issue for authors that are dealing with
text-based content, and that if you author multimedia you give up
device-independence by definition.

See http://www.cwi.nl/~jrvosse/talks/bristol/ for slides and paper.

Many of the other talks illustrated the current attempts by content
providers to make device independent content for WAP and interactive
TV.  This often (always) fails because of:

 - lack of standardization (a Microsoft guy discussed more than 9
 "international standards" for interactive TV)

 - underspecified standards (a phone.com guy explained how two
 WML-compliant phones interpreted the same WML-cards completely
 differently)

 - hugely diverse devices (a Nokia guy explained the many differences
 that exist among all the Nokia phones: landscape versus portrait
 screens, various screen sizes, resolution, color depth, voice
 interface/full keyboard/phone keyboard, etc)

There was also consensus about the fact that there are different
levels of device independence, each level might require a different
approach.  E.g. there is a big difference between making the same
content available for two different WAP phones or making the same
content available for a WAP-phone and as a fully fledged SMIL
presentation.  The problems in the first case are perhaps better
solved on the client, the second case on the server.

Also the problem of offering alternatives using a fine versus coarse
grained split up (in SMIL terms: have one switch at the root of your
document tree or many switches at the leaf nodes) was discussed, and
the consensus here was that it was good to allow both options (as is
the case in SMIL), but that in general DIA requires something at a
higher level than this "#ifdef" style of authoring.  Alternatives such
as transcoding existing HTML into other formats is often used, with,
as expected, very limited success.  More viable seems the use of the
same database back-end with different templates for HTML, WML etc.
Issues here are the level of device independence of the database
content and the control the content author has over the end result.

The presentation about UIML (user interface markup language, see
www.uiml.org for more info) was a typical "this is cute but does it
scale" type of presentation.  The idea of UIML is that you define your
user interface at an abstract level in XML, and then provide mappings
from this model that define the realizations using Java/MFC/Qt
widgets, HTML forms, WML, etc.

Another recurring trend was the wish to get from a "page-oriented"
model to an "application-oriented" model.  This came up with the
WAI-compliance checkpoints, which assume a page by page assessment to
award a zero (not accessible) to "AAAA" (very accessible) status.  How
can a site with an large/infinite number of database generated pages
get a AAAA status?  Same for WAP: you want a whole (part of a) site to
be available on your phone, not a random set of pages within a site.
Same for voice browsers, where the page is replaced by a dialogue
metaphor.  It also came up when authoring support was discussed: tools
need to ensure a complete application has certain characteristics,
instead of the current page-by-page metaphor.  The application
metaphor also implies that device independent user interaction, event
handling, etc is at least as important as device independent
presentation.