Steven Pemberton, CWI, Amsterdam and W3C
Chair, W3C HTML and Forms Working Groups
Editor in chief, ACM/interactions
User interfaces for all
But what a mess!
Both in design and use ...
XHTML is trying to improve the situation
XHTML is a family of XML-based markup languages.
Currently:
And soon: XHTML 2
We are currently working on a new member of the XHTML family, in our minds the real XHTML.
Our aims are:
In fact as I will show, many of these things are intertwined.
By 'generic XML' we mean: if a facility exists in XML technologies, and it is suitable, use it and not a special-purpose XHTML facility. Try to get missing functionality added to XML.
Examples:
Major missing functionality: Linking (XLink insufficient for XHTML's needs).
Advantages: less variability; more interoperability; much of XHTML 2 works already; opportunity to make a cleaner break.
Remove all presentation-only markup.
Use stylesheets to define presentation.
Advantages: possible to author once, and display on different devices; better presentation possibilities; device presentation not hardwired; CSS has support for devices; more accessibility.
.
Power of CSS currently seriously underappreciated.
(Note: doesn't require CSS to be implemented; just uses its model)
Add more semantically-oriented markup to make documents richer.
Examples: <line> element instead of <br>. <section> and <h> elements instead of <h1> <h2> etc
Not
I think that I shall never see<br> A poem lovely as a tree
but
<line>I think that I shall never see</line> <line>A poem lovely as a tree</line>
Advantages: more presentational opportunities (folding,
marquee, numbering)
[More shortly]
Forrester did research among 8000+ users on why they chose one website above another equivalent one. Reasons were:
Forrester did research among 8000+ users on why they chose one website above another equivalent one. Reasons were:
Forrester did research among 8000+ users on why they chose one website above another equivalent one. Reasons were:
Forrester did research among 8000+ users on why they chose one website above another equivalent one. Reasons were:
Forrester did research among 8000+ users on why they chose one website above another equivalent one. Reasons were:
Forrester did research among 8000+ users on why they chose one website above another equivalent one. Reasons were:
All other reasons were 14% or lower.
There are two principal 'users' of XHTML:
observe incorrect current use; identify other areas
the design of the markup can affect the end user's experience
For instance client-side image maps compared with server-side ones:
Client-side image maps give better usability by allowing feedback to the user about where is clickable, and where a click will lead to.
But they also give more accessibility, by allowing accessible software to create an equivalent navigation control.
As an example of poor usability, current frames are a disaster!
Currently devising XFrames, a replacement for Frames.
One day we will all be grateful for accessible websites. Maybe even today.
As an example of a current problem: <h1>, <h2> etc are mostly terrible for accessibility, because no one uses them right, and it is hard to work out document structure from so little information.
<h2>Chapter 1</h2> ... <h3>Section 1</h3> ...
is now:
<section> <h>Chapter 1</h> .... <section> <h>Section 1</h> ... </section> </section>
More structure gives more accessibility.
Observe how scripting is currently used.
Identify missing markup/functionality.
Add it where possible; try to cover 80% mark
Examples: menus for navigation; forms data checking; folding presentation.
Advantages: more devices, more presentational variations, better search, better accessibility
Less scripting
No hard-wired presentation
Events
New Forms
Current HTML events are a disaster
Problems include:
XML markup binding to DOM2 Events
Extensible for new event types
'Abstract' events can replace the old device-dependent ones (e.g. 'activate' instead of 'click')
Independent of scripting language
Can entwine event markup in document, or can separate it out
Advantages: more types of events, other types of scripting (e.g. declarative), more device independence, more accessibility
<a onClick="...javascript..." ...>
becomes
<a ev:event="activate" ev:handler="#myhandler" ...>
HTML forms have proven their worth, and are the basis of the ecommerce revolution. XForms improves on them:
Essentially defines two separate parts: the 'real' form (data, datatypes and submission details), and form controls bound to the data.
XForms 'native' form controls are device-independent, and accessible, though a language may define its own.
Advantages: usability, accessibility, device independence
<input ref="order/shipTo/street">
<label>Street</label>
<hint>Please enter the number and
street name</hint>
</input>
A user agent has a default presentation.
If the user agent supports it, a stylesheet can be used to define other presentations.
<select ref="icecream/flavors">
<label>Flavours</label>
<item><label>Vanilla</label>
<value>v</value></item>
<item><label>Strawberry</label>
<value>s</value></item>
<item><label>Chocolate</label>
<value>c</value></item>
</select>
This example covers both radio-button style selection, and menu selection: not encoded in the control.
We want:
But can we achieve this just through good design?
Well, we've got a friend.
"Google is, for all intents, a blind user. A billionaire blind user with tens of millions of friends, all of whom hang on his every word. I suspect Google will have a stronger impact than [laws] in building accessible websites."
...
"In a world where Google likely has a valuation several orders of magnitude higher than any chrome such as flash, graphics, audio, interactivity, or "personalization", I see a heady revision."
Karsten M. Self
Things to avoid:
In other words: avoid things that are bad for accessibility!
HTML was originally designed as a structure description language, not a presentational language.
The design of XHTML is truly 'radical': taking HTML back to its roots.
Device independence, accessibility and usability are surprisingly closely related.
Even though website builders may not yet know it, device independence, accessibility and usability have a major economic argument in their favour. Spread the word!
More information: www.w3.org/Markup, www.w3.org/WAI
and soon I hope: UIG