Only show new notifications on the lock screen?
This is a continuation of the discussion here.
For a while I've thought that we should only show new notifications on the lock screen - ie. notifications that have appeared since the device locked. The reason for this is that, in my mind, notifications on the lock screen exist to show you what's happened while you've been gone rather than being an overview of all your outstanding reminders.
The new lock screen design was someone based on this assumption. See how we show counters for each notification source - that's a count of "how many things have happened since you were away".
(To be honest, I thought that only showing new notifications was what we'd done in the past, and we'd regressed at some point, but it seems that I'm mistaken in that regard.)
Clearly there are various possible approaches to this question, each of which has value:
- Just show new notifications: provides a way to check whether it's worth unlocking, and tells the user what they might want to look at once unlocked.
- Just show unseen notifications: a reminder of things that you haven't seen.
- Show all notifications: acts as a reminder of all your outstanding events.
One issue with 2 is that, since the notifications are stripped of their content on the lock screen, there's no way to differentiate between a seen and an unseen notification.
It's worth noting that mobile devices do both 1 & 3: at least on Android, if you pick up the phone you see icons for events that have happened while locked, and if you wake up the screen without unlocking, you get a list of all outstanding notifications.