The inevitable tradeoff here is having a somewhat standardized location for notifications versus allowing them to appear arbitrarily determined by the developer’s notion of where they are ostensibly drawing your attention. Maybe that’s worthwhile, but I think there are going to be a lot of cases where the ideal location is ambiguous, or where devs have an idea for where your attention will be that’s not always correct, or where bad actors exploit this flexibility to make it look like something it isn’t in an effort to trick users. I don’t know the right answer to what might be best, but I tend to think that standardized features should be preferred when in doubt.
It's not standardized. And putting notifications on or right next to a control you're INTERACTING WITH is not "arbitrary" at all; you must be looking at it, because you're using it.
Doesn't it depend on your platform, and isn't experimentation the way things become standardized?
User notifications on MacOS are definitely standardized, but originally they were Growl notifications until Apple made it a first-party API and iterated on it.
Some conventions transcend platforms. The aforementioned greying-out, for example. And sure, we have to try something for it to become a standard. But in the end the standards percolate up because they're intuitive. The controversy over some of these "toasts" shows that they don't meet that bar.
And you are right in that the Growl-style notifications in Mac OS are standard now... but those are different from the ones in question here because they are not related to a control that the user was just manipulating. They could come from anywhere at any time, and thus they must be presented in a location independent of whatever the user is doing.
The Growl-style notifications work well because they're near the top of the screen, too. Users are used to status and information in menu bars and so forth, in accordance with the general top-down convention of presenting information.
Thinking it through, I did actually implement a "toast"-style alert for asynchronous issues in one application. It was at the top of the screen, though. I originally put it in there strictly for debugging, but I think I might have left it in the release. So I'm not entirely opposed to the idea, but mainly its placement in the examples discussed here.
What if another thing errors at the same time? If you put the error just where you clicked it, you may well miss it. If all things like that happen in the same place (e.g. bottom right) then you won't.
It's pointless pretending there's one perfect guiding philosophy and all others are obviously wrong.
Depends on gap between the interaction and notification. If the person has already moved on from the page, then next to control is not possible. In which case notifications at some standard position makes more sense.
