When you click into the detail view of individual segments, what’s the little stars icon for? It seems to get rid of a lot of the individual segments, but what is it actually doing?
Also, why do some entries have only a couple of blue dots on the map, while others have dozens? Are those each an individual segment? How does the app decide to break up segments?
Good questions! Two related things going on:
The stars (
) icon — “Cleanup samples.” Each visit or trip is built from lots of individual location readings, and each reading carries its own guess at what you were doing (walking, stationary, driving…). Those guesses can be noisy — a stop picks up a few stray “walking” readings, or a walk gets the odd “stationary” one — and that noise is what chops one stop or trip into lots of little segments.
Tapping the stars button tells Arc “this whole thing really was just a stay / a walk / a drive”: it confirms the readings to match, marks any stray outliers as bogus, and reprocesses. A segment is just a run of consecutive readings of the same type, so cleaning up the noise collapses all those fragments back into one (or a few) clean segments. As a bonus, those confirmations also feed Arc’s on-device activity-type learning, so it gets a little better at similar situations next time.
The map markers + segments. Good instinct — yes, those are the individual segments themselves. A couple of them means the period stayed clean and consistent; lots of them means it got chopped into many little segments because the activity type kept changing from one reading to the next (walk → stop → walk shows as three). So a “noisy” stretch ends up with lots of segments — which is exactly what the Cleanup button collapses back down.