- shorter keying time
- less errors
- more preferred by users
I-c seems to be the best: shorter keying time and less errors. And yet this is not the standard.
VI-a is (at least in Europe) the standard phone pad. Also, this is the standard for the PIN Bancomat
I-a is (over here) the standard calculator pad.
I can see why I-c is good for phones - the numbers are layed out further apart -> less error prone.
Comparing VI-a and I-a : I can see why the calculator layout is good for calculators. Random numbers will obey Benford's Law, that states that 1 is more frequent than 2, which is more frequent than 3, and so on.
So the lower numbers are more frequent. And these are on an easy-to-find spot on the calculator; on the bottom row. Which is easier to find "blindfolded" than a row somewhere in the middle of the device. Telephone numbers may of may not obey Benford's Law. If they do not, any distribution is fine. And in that case, ordening the numbers top-down seems more logical - list are mostly ordered from a lower number on top, to the highest number below. Think of the Top 40, where #1 is on top. Furthermore, a phone has less buttons than a calculator, and the row 1 2 3 is usually very easy to find as well.
Thoughts?
What would this mean for our typing keyboards?
or maybe not....