Dial

Tessel is a calendar people check before they get out of bed. Its alarm sheet used three text fields, and half of the people we watched set the wrong hour on the first try, still half asleep.

The fix was older than the bug: a drum you flick with one thumb, that coasts and settles on a row with a small tick, so you can set a time without reading it.

The coast. A flick has to land on a row, not between two, so the wheel projects where your throw would stop and bends that point to the nearest row before it starts to slow down. You never see it correct itself.

The tick took a week of its own. It fires as each row crosses the band, not when the wheel stops, and it drops out entirely above a certain speed so a fast flick sounds like a ratchet rather than a buzz.