Craig Hockenberry, back in 2008:
But on the iPhone, you have a limited area and associated mechanisms for getting the user’s attention. In effect, it creates a notification bottleneck.
This notification bottleneck forces the user to work when figuring out who needs attention. First they have to recognize the notification by sound, feel or sight (or a combination of those senses.) Then they have to navigate to the recognized application, which may not be easy given the phone’s current state. Finally they need to deal with the source of the notification. Now imagine doing all this frequently: the network will end up being a constant source of distraction.
If you’re still unconvinced, let me ask you one final question: do you want to get IM notifications while you’re making a 911 call?
As I’ve said before, notifications on the iPhone (and iPad, for that matter) suck. Android (and WebOS, for that matter) get it right — a single place for all notifications to live. While the sounds may vary, if an app needs your attention on those platforms, it will be apparent.
I hope this is an issue Apple address with the announcement of OS 4 in a few hours. I know most people are clamoring for multi-tasking. I know I am — at least on my iPad — but multi-tasking without better notifications is going to make the current problems in Apple’s notification scheme far worse.