Chapter 23: Accessibility Testing

Accessibility testing for scanning is mostly about timing, visibility, and error recovery. Aim for repeatable checks.

Core tests

• Single-switch simulation: Use only Space to test all paths.
• Timing sweeps: Test slow/medium/fast rates.
• Error drills: Practice undo, cancel, and recovery.
• Fatigue runs: 20–30 minutes sustained use.

Measurement Checklist

• Record TER, scanning errors, and reaction time before and after changes.
• Verify that any highlight is visible in low light and bright light.
• Confirm the user can recover within two scan cycles.
• Validate at least one “safe mode” configuration.

Common failure modes

• No undo/back path
• Highlights too subtle
• Scan loops never end
• User can’t recover from a mistake in under two cycles