Tap each target as quickly and accurately as you can.
Available after the first measured trial.
Complete 5 varied trials to see your trend.
Scatterplot of movement time against index of difficulty. No measured trials yet.
Fitts' Law formulas:
ID = log2(D / W + 1) bitsMT = a + b × ID milliseconds
D is the distance to the target, W is the target diameter,
a is the intercept, and b is the slope in milliseconds per
bit. Targets take longer to reach when they are farther away or smaller. Your dots
show each attempt; the trend line estimates how movement time changes as difficulty
increases. In interface design, larger targets placed closer to where the pointer
already is are usually faster and easier to select.