"The short stories were unbelievably bad."
Translation:Novellene var utrolig dårlige.
'Novelle' is a wide (and vague) genre in Norway, which indeed covers both what you would call short stories and novellas. It pretty much covers any fictional prose shorter than a 'roman' (novel) which doesn't fit into a more narrow genre such as 'eventyr' (fairy tales).
Store norske leksikon entry on 'novelle'. (in Norwegian)