Data-entry keyboard geometry and keying movement times.

Area of Science:

• Human-Computer Interaction
• Ergonomics
• Usability Engineering

Background:

• Understanding keyboard ergonomics is crucial for efficient human-computer interaction.
• Existing models, like Drury's (1992), describe keyboard movement time based on physical parameters.
• Further investigation is needed to refine these models and account for all performance factors.

Purpose of the Study:

• To investigate the impact of key size and inter-key spacing on keyboard user performance.
• To evaluate the predictive accuracy of Drury's model under varying keyboard configurations.
• To identify any unpredicted factors influencing typing movement time.

Main Methods:

• Conducted experiments using fifteen simulated keyboards with systematically varied key sizes and inter-key spacings.
• Measured user movement time during target key selection tasks.
• Compared experimental data against Drury's established movement time model.
• Performed a follow-up experiment with marked target keys to isolate effects.

Main Results:

• User movement time was accurately predicted by Drury's model for most configurations.
• Minimum movement times were observed when inter-key spacing approximated finger pad size.
• An effect of the number of keys moved was identified, which was not accounted for in the original model.
• This effect persisted even when target keys were clearly marked.

Conclusions:

• Keyboard layout, specifically inter-key spacing relative to finger size, significantly influences typing efficiency.
• Drury's model provides a good baseline for predicting keyboard performance but requires refinement.
• The number of keys involved in a movement is an additional, unmodeled factor affecting typing speed and accuracy.