Me too and this was not the question of my original email. I wanted  
to understand what heuristics
I could use when I'm programming to use (if any) exceptions in my  
code. And this meta question
was raised when I look at the tests the students were writing.

>
>   [map at: key] on: KeyNotFoundError do:[:ex| ex return: "something"].
>
> Personally, I really don't want to move over to the latter style.
>
> Cheers,
>   - Andreas