unity-design team mailing list archive

[Ralph Green <sirable@xxxxxxxxx>]

On 5/19/11, Ed Lin <edlin280@xxxxxxxxx> wrote:
> On Thu, May 19, 2011 at 10:03 AM, Ralph Green <sirable@xxxxxxxxx> wrote:
>>  2. MPT seems to think the global menu is quicker, even on large
>> screens.   That is certainly not my experience.  ... The
>> question is how typical am I?
>>  3. Why do people keep referring to Fitt's law.  It does not apply to
>> 2 dimensions, as best as I can tell.  Shouldn't the discussion be
>> about steering law?
>> Ralph
>
> Fitts's Law is the best measurement we've got for the concrete
> problem. For what it describes it is absolutely accurate and helpful.
> However it's only part of the equation and sometimes this is
> forgotten.
>
> A button on the screen edge is faster to access than a button anywhere
> else on the screen, except directly beneath the mouse pointer. This
> applies universally to everyone who knows how to use a mouse and uses
> proper acceleration. If it doesn't for you, "you are doing it wrong",
> the testing or the mousing ;)
 If this is some kind of principle that guides the decision to use
the global menu, then it is time to change.  I am quite experienced
with the mouse and how to use it.  I use as much acceleration as is
reasonable.  It would not be an improvement to have the mouse go
twitching away out of control, which is what happens if I speed it up
more than it is now.  So, the distance is not irrelevant.  If Fitt's
Law is considered important, how can the distance be irrelevant?  It
is one of the variables that most drives the result.  If you ignore
distance, you are not using Fitt's Law, but rather an arbitrary
derivation of it.
 Concerning my query about Fitt's Law, I note this quote from wikipedia:
 "It applies only to movement in a single dimension and not to
movement in two dimensions (though it is successfully extended to two
dimensions in the Accot-Zhai steering law);"