Re: radio buttons

[Calum Benson <calum benson sun com>]

Chris Elston wrote:
> The value that the radio buttons are supposed to represent is optional but
> if selected has one of three values.  Therefore, I'd like to begin the
> list unchecked so that the user can opt not to check any.

In this case, from a usability point of view, a fourth radio button that
indicated "none of the above" is probably a better solution.  As well as
just looking odd, groups where "none selected" is a valid state offer
the user no obvious way to get back to that state after they've selected
one of the buttons.  

They also potentially interfere with keyboard navigation, since when
tabbing into a radio button group, focus should really go to the
currently-selected button in that group. It might be okay to give focus
to an unselected button if you can see that all the others are
unselected too, but it would probably confuse the hell out of a blind
user...

Cheeri,
Calum.

-- 
CALUM BENSON, Usability Engineer       Sun Microsystems Ireland
mailto:calum benson ireland sun com    Desktop Engineering Group
http://www.sun.ie                      +353 1 819 9771

Any opinions are personal and not necessarily those of Sun Microsystems