Waze: a road report can be accurate and still become outdated
Waze lets drivers report hazards and uses later feedback to adjust how long reports remain visible. The design treats freshness as part of the information service rather than leaving every once-correct report on the map forever.
Form your own approach first, then explore the reasoning to check trade-offs and validation you may have missed. There is no single right answer.
When availability reports go stale, who is responsible?
A campus laundry room wants students to report when washing machines are available. The walk from the dorm takes five minutes, so someone else may occupy a machine before a student arrives. After an unsuccessful trip, a student may distrust a reporter even though a machine really was free at the time.
- Design reporting, viewing, and arrival feedback. Decide how to show observation time and uncertainty, which feedback affects a report’s useful lifetime, and whether the reporter should be rated.
- Walk through A reporting two free machines and B arriving five minutes later to find none. Deliver a one-page proposal explaining when the information disappears, who must do an extra step, and how to judge whether the design reduces misleading information without discouraging contributors.
Explore the reasoning
Separate an observed fact from a guarantee about the future. Compare a fixed expiry, arrival feedback, and simply showing the observation time. Check whether B’s bad experience necessarily means A was wrong, then choose a behavior you most want to change and observe.