Chapter 21: User Profiles

Different users need different configurations. Treat profiles as stable baselines that can be tuned, not as fixed diagnoses.

What a Profile Should Capture

• Input capability: mean switch press time, variability, and acceptance delay needs.
• Visual preferences: highlight size, contrast, animation speed, and symbol size.
• Cognitive load: grid size, scan pattern complexity, and prediction usage.
• Fatigue: how settings should shift over time or after prolonged use.
• Environment: lighting, noise, and seated vs. reclined positioning.

Example Profiles

• Athetosis: longer acceptance delay, slightly slower scan, higher tolerance for missed first-row selections.
• Degenerative conditions: “fresh” vs. “fatigued” presets with different scan delays and prediction lists.
• Low vision: high contrast, thicker borders, larger highlight area, fewer items per row.
• High cognitive load: smaller grids, fewer modes, predictable scan order.

Practical Tips for Teams

• Always keep a “safe” fallback profile that is slow and forgiving.
• Version profiles and log when changes are applied.
• Use short tests to validate profile changes before daily use.