Re: [Usability] Re: Button ordering

[Seth Nickell <snickell stanford edu>]

> I feel compelled to point out that for consistency, it's not the
> [ OK ] button you should be talking about. It should be the button
> the user will usually want to push. e.g.
> 
> 
> > |    Are you sure you want to format your entire hard drive?   | 
> > |                                                              |
> > |                                        [ Cancel ] [   OK   ] | 
> > `--------------------------------------------------------------'
> > 
> 
> "uh... ok." Would be a bad thing most of the time.

First a minor caveat... the dialogue you list *is* ambiguous and could
certainely lead to users formatting their hard drive when they don't
want to. I think if the dialogue were done better it would be much safer
(I explain some of the principles behind my redesign at the end, but
basically this is just following the GUP dialogue guidelines):

 ----------------------------------------------------------------
 |                                                              |
 |    WARNING: Are you sure you want to format your hard        |
 |             drive? This will erase all data on the drive     |
 |             including documents and applications.            |
 |                                                              |
 | [ Help ]              [ Cancel Format ] [ Erase Hard Drive ] | 
 `--------------------------------------------------------------'

The specification currently puts the affirmative button on the right, 
whether that is the "default" button or the "safe" button or not. That 
means that the [ OK ] button in the above example would indeed go on the
right. I think it would actually be rather dangerous to reverse the buttons, 
particularly in unusual potentially dangerous circumstances like the "format 
your hard drive case". Users will become accustomed to the right choice being
affirmative, because it probably will be in most situations such as save 
dialogues. When they encounter a dangerous dialogue, it would be foolhardy 
to reverse the buttons! That would be asking for the user to make a 
mistake and click on the wrong choice.

I would argue that you are talking about safety here, not "the button
the user will usually want to push". I would guess that most people that
get to a "format your hard drive" will want to push OK, because if we
did it right that won't be something that's easy to accidentally access.
In most dialogues the user encounters the "default" choice will be the
affirmative, often that won't even be the safest choice. For example, in
a "Save" dialogue one could argue that the safest choice is "Don't Quit"
(commonly called "Cancel" in existing save dialogues) not "Save". If we
are displaying a dialogue its probably because there really is no
obvious "right" choice. If there's an obvious "right" choice, we
shouldn't display the dialogue. Similarly, since the dialogues displayed
should be actually important, we shouldn't be training users to "always
click the right button", because that simply won't be what they want.

There are also effiency reasons for affirmative being on the right
rather than "default". Assuming the dialogues we pop up are actually
ones users care about, and they actually are making a choice,
affirmative on right negative on left is a very simple pattern for users
to learn. Its obvious! Simple obvious things are ones that actually help
people. If you're pattern becomes to complex and tries to out-think the
user, the will not form a mental model that matches the design model and
will probably be impeded or frustrated. With affirmative on the right
you learn "I agree to what this dialogue says by clicking the button on
the right". If GNOME becomes consistent in using this, the user will
start to automatically learn to move their mouse to that button when
they agree with the dialogue. It takes that much more thinking out of
the process (note that this decrease in thought is exactly what makes it
dangerous to reverse the button order sometimes). If we try to predict
which they will want to do, they will still have to read all the buttons
every time to make sure that the one we predicted is the one they
actually have to do. All the effeciency reasons for doing a firm
ordering of the buttons go out the window!

Also, the text of the dialogue should probably include "WARNING:" and a
note about the consequences. Additionally, the word "format" is probably
not scary enough "Erase" is probably better. Also, you are missing the
help button which I think is *really* important in a frightening
dialogue like this.

I think if the dialogue above were done well it would not be a
significant danger to have the "affirmative" be the destructive action,
and it would actually be dangerous to reverse the affirmative and
negative.

-Seth