[Zarathustra30]

I've actually run into this in the wild, with regards to sales forecasting. A program we were using returned zero if the error bars on a forecast were over 100%. For example, selling somewhere between 1 and 7 units, but averaging 3.

Returning 3 was "wrong", but infinitely more correct than retuning 0.

[taneq]

That sounds like zero was meant to be treated as a special error value? If so then “bad forecast” is more correct than “everything’s fine here, situation normal”, no?

Of course this is far from the best way to do this.