[dinkblam]

> The phenomenon that something which was previously working correctly, suddenly does not work correctly when one tries to demonstrate the operation to others.

the same word is also used for the reverse situation, i.e. if something that did not work suddenly works when trying to demonstrate the failure.

think bug reporting e.g. at the car mechanic, warranty claims, etc. if you try to show a reproducible bug to others, it suddenly vanishes...

[jprete]

Is the word only for unpleasant surprises, or for all such situations, even when the surprising outcome is also a good one?

[dinkblam]

i've never seen it used for pleasant surprises. its basically if you want to show something (even something that does not work, like the engine-not-starting) and the demonstration does not work as expected.

[namibj]

They only have to be "unpleasant" in some aspect, for example because you now annoyed/bothered you team lead. The unexpected behavior itself can still be desired, with the unpleasantness restricted to the demonstration itself.