[Usability] Familiarity, Accessibility, and Survival of the Fittest

[Gregory Merchan <merchan phys lsu edu>]

Placing a dialog-like closing button on a window makes it appear as
if changes in the window will not immediately affect anything else
because controls within dialog windows do not affect anything else
until a button like Apply or OK is pressed. (And, as usual, I mean
dialogs as those windows that have buttons like OK and Cancel - not
just any window that doesn't contain a document.)

An instant-apply window, regardless of the presence or absence of a
closing button, may be a hinderance to accessiblity when feedback
about changes is to be provided continuously. (Imagine, if you will,
either many visual changes or some computer voice droning on and on.)

Most people using computers now are Windows users. Windows does not
provide instant-apply and such a thing will probably confuse people
used to that system. Also, CDE and KDE do not provide instant-apply;
those are the other widely used X desktops, and few (if any) other
applications support instant apply - GNOME apps would seem quite odd
running alongside them. The only users accustomed to instant-apply
are those that have used MacOS or OS/2, and they are small in number
and would expect a certain kind of interface to an instant-apply
window.

Windows, CDE, and OS/2 at some stage all used the same button order
and placement in dialog windows. This order was the order which we
are now using, except in mirror image and without space between Help
and the other buttons.
 I.e.:
  |
  | [   OK   ] [ Cancel ] [  Help  ]
  +------------------------------------------

This may not be the way these platforms show dialog buttons now - I 
think Windows now uses this order but pushed against the right-side -
but it is the arrangement that was common to all of them and provides
consistent placement of the OK button. This with Help right-aligned -
i.e., the mirror image of what we have now - would keep Help
consistently placed too. In any case, this places OK as the first
button in a tab navigation sequence; which may be desireable.

(Whether buttons such as Apply or Reset would appear between OK and
Cancel, or after Cancel is another matter. Since Cancel would be more
common than either Apply or Reset, I think placing it consistently
next to OK would be beneficial; though I hold no strong opinion about
this arrangement . . . yet  ;-)

A non-instant-apply environment is familiar, accessible, apt to be
usable and accessible regardless of the window manager, and similar
to other applications on X. The mirror image of our current dialog
button order seems to provide many of these same benefits.

Perhaps the best fit for GNOME is to be like these other
environments, but more capable, more accessible, much faster,
and much better looking.


Gregory Merchan