PFWG comments on View Mode Media Feature

This is a review of the Last Call draft of the View Mode Media Feature
located at:

http://www.w3.org/TR/2010/WD-view-mode-20100420/

This is a formal response form the Protocols and Formats Working Group.
Approval to send this response is archived at
http://www.w3.org/2010/05/19-pf-minutes.html#item06. Our thanks to
Gregory Rosmaita and Gottfried Zimmerman for preparing this comment.

The Last Call draft of the View Mode Media Feature states that it
"Applies to: visual and tactile media types"
http://www.w3.org/TR/2010/WD-view-mode-20100420/#the--view-mode--media-feature


While these view modes make sense for visual media types, they don't
seem appropriate for the two tactile media types "braille" and
"embossed", as defined in "Cascading Style Sheets Level 2 Revision 1
(CSS 2.1) Specification". in Section 7.3 "Recognized media types"
http://www.w3.org/TR/CSS2/media.html#media-types

Please consider the following:

1. A user using a screen reader with a braille display. Should the user
agent switch to the CSS rules defined for media type "braille"?   This
would be odd and unexpected behavior, since the primary interaction mode
is visual. (Note: There are windows on a screen that the screen reader
reads out and feeds the braille display).

2. In a pure tactile interaction environment which is not mediated through
a visual screen, does the WIMP (Windows, Icons, Menus, Pointers)
interaction model make sense at all?  It could make sense in a 2D tactile
pin matrix environment where raised dots are used to present letters
(braille) and graphical strokes, and these dots can be used for
interaction with the user.  But it does not make sense for the current
media type "braille" (which is meant to be a continuous stream of
characters), and not for "embossed" (which is meant to be a static
printout in braille).

3. 2D tactile interaction environments are not yet common.  Should there
be an additional tactile media type for 2D tactile interaction (such as
"pinmatrix" or "2dtactile")? In research or for early adopters, is there
already a commonly accepted interaction vocabulary for 2D tactile displays
(such as the WIMP for visual displays)?  Or does the Web Applications WG
propose to go with the WIMP model for simple transfer between the visual
and the tactile representation?

In light of these points of ambiguity, Unless the Web Applications WG can
define what the view modes -- "windowed", "floating", "fullscreen",
"maximized" and "minimized" -- mean for the media types "braille" and
"embossed", the PFWG advises that it would be better NOT to apply
'view-mode' to tactile media types at the current time.

The PFWG welcomes the opportunity to discuss these issues with the Web
Applications WG to ascertain what the view modes defined in the View Mode
Media Feature means for the media types "braille" and "embossed" and
would like to work in concert with the Web Apps WG and the CSS WG to
refine and define what these concepts mean for the "braille" and
"embossed" media types.
-- 

Michael Cooper
Web Accessibility Specialist
World Wide Web Consortium, Web Accessibility Initiative
E-mail cooper@w3.org <mailto:cooper@w3.org>
Information Page <http://www.w3.org/People/cooper/>