Throughput captures a pointing device's speed-accuracy tradeoff, not speed alone

What it is

Pointing throughput is a rate measure that combines target-acquisition speed and precision, often expressed as effective information transmitted per second. It is not movement time alone: a device that moves faster but misses often or requires large corrections may not have higher throughput.

Why it happens

Target acquisition has a speed-accuracy tradeoff. Throughput combines task difficulty with actual completion time and, in standard calculation, uses endpoint variation to form an effective width, penalising fast-but-imprecise strategies. It evaluates device, person, and control-display mapping as one channel under a particular task.

Studying it

Use repeated target acquisition across distances and widths, recording movement time and endpoints to calculate effective difficulty and throughput per participant or condition. Report device, gain, display, posture, practice, error handling, and calculation; one mean number cannot establish a fair comparison.

Where it stops holding

Throughput chiefly describes discrete two-dimensional target acquisition. It does not replace evaluation of text entry, continuous drawing, multi-finger gesture, or a full workflow. Different tasks and conventions yield different values, so a number from one experiment is not a permanent cross-context hardware property.

Applying it

• When selecting or tuning pointing input, record speed, error, and throughput together rather than choosing by fastest completion alone.
• Hold task difficulty, display configuration, and practice condition constant before comparing devices or settings.
• Use throughput to find whether a speed gain trades away accuracy, then inspect endpoint error and corrective behaviour.

Related

• Same group: C1.15.2 Fitts' law models movement time as a logarithmic relation to target distance and width · C1.15.3 Effective width is recalculated from endpoint distribution rather than nominal width · C1.15.4 Throughput across tasks and postures cannot be compared directly · C1.15.5 Mean completion time alone hides speed-accuracy differences
• Nearby: C1.03 Control-display gain · Q1 Research methods and evaluation
• Search terms: pointing throughput · speed-accuracy tradeoff · target acquisition