Fitts's Law Pointing Experiment

Fitts's Law is the foundational quantitative model of human-computer interaction: it predicts how long a pointing movement takes as a function of the distance to a target and the target's size. This simulator turns the model into a real, working experiment rather than a static formula. You click through a series of targets arranged in a circle at varying distances and widths, and every movement is genuinely timed with the browser's high-resolution clock while your exact click coordinates are recorded relative to each target's center. After you complete every distance/width condition, the simulator fits your own personal Fitts's Law constants (a and b) to your measured data with linear regression, and reports your measured throughput in bits per second using the ISO 9241-9 Shannon formulation — the same evaluation method used in real pointing-device research.