Progress
Inline validation
Effort: Low
What to notice
Leaving a field shows a check for valid input or a fix for errors, right away.
How to build it
- Validate when the field loses focus, not only on submit.
- Say in words what to change and how.
- Do not flag errors on every keystroke while typing.
Measure
- Main metric
- Successful submission rate
- Guardrail
- Error messages shown
When it backfires
Errors before people finish typing feel like scolding.
Theory behind it
Response-time limits
Under 0.1 seconds feels instant, under 1 second keeps the flow of thought, and over 10 seconds loses attention.
Well supported
Game feel
When motion, sound, and light answer an input instantly and pleasantly, touching becomes fun in itself.
Practitioner framework
Flow
People become absorbed when challenge matches skill and goals and feedback are clear.
Well supported
Playable demos
Try the same mechanism in a playable demo.