The SE definition of "answered" question is: has an answer that is either accepted or has positive score. But the search parameter isanswered
appears to ignore the "accepted" clause: when set to "no" it still returns questions with an accepted answer, as long as it has 0 score.
Sample query to reproduce the bug (unless meta effect kicks in and the answers get upvotes).
By the way, it seems that isanswered
works only when is:question
is present, but I'm not complaining about that... yet.
Also, this parameter is not listed on the advanced search help page, but I'm not complaining about that either... yet.
isanswered:no
does. – user259867 Feb 24 '15 at 19:36