[Sigia-l] A matter of reliability

[Michael Albers]

The important thing about knowing Fitt's law is being able to 
understand what changing the size of a target does.  It's a log 
function rather than a linear function, which is how most people 
mental extrapolate.   No, you don't have to really crunch the 
numbers, but it helps to know how they will change.

Lets say that people are misclicking or other designers want to make 
targets smaller to free up screen space for other stuff.  Either way, 
at least the real formula can give you an idea of the possible 
effects.  Just knowing a smaller target is harder to click is 
intuitive, but hard to interpret with respect to how it will affect a design.

Mike


>I wonder if the field of IA/UX would be better off if we all understood the
>following equation:
>
>    MT = a + b log2(2A/W + c)
>
>Or is it enough that we understand the following, non-scientific and easily
>understood phrasing of the same concept:
>
>    "The time to acquire a target is a function of the
>    distance to and size of the target."
>
>Or even:
>
>    "It's harder for users to click links that are
>    small and far away."


------------------------------------------
Dr. Michael J. Albers
Professional Writing Program
Department of English
University of Memphis
Memphis  TN  38152
malbers at memphis.edu