Estimate pointing time with Fitts's law and choice time with Hick's law to compare layouts

After: what comes back

The first lines of a real run on that input. Nothing here is edited by hand.

# Fitts and Hick-Hyman estimates

Fitts (Shannon form): time = a + b * log2(distance / width + 1), with a = 100 ms and b = 150 ms per bit. Hick-Hyman, equal-probability choices: time = a + b * log2(choices + 1), with a = 200 ms and b = 150 ms per bit.
Both are models. The default constants are typical orders of magnitude for mouse pointing and simple choice reaction (pointing b is often reported between about 100 and 250 ms per bit; choice b near 150 ms per bit), not measurements of your users, your device or your task. Pass your own a and b if you have fitted them. Treat results as a way to compare layouts, not as predicted seconds. Fitts: Paul Fitts, 1954; Shannon formulation after I. Scott MacKenzie. Hick-Hyman: W. E. Hick 1952, Ray Hyman 1953. Not verified against the design library; stated from general knowledge.

## Choice set
6 equally likely choices: 2.807 bits, decision time about 621 ms. The model assumes a familiar, well-ordered set; it does not hold for unfamiliar items or when people scan a list.

## Layout comparison
Each layout's time is the decision time (if choices given) plus the pointing time for each target in order.
... full output on the tool page