DOC Fix grammar in docs
@@ -87,7 +87,7 @@ is then the average of the values computed in the loop.
This approach can be computationally expensive,
but does not waste too much data
(as it is the case when fixing an arbitrary test set),
-which is a major advantage in problem such as inverse inference
+which is a major advantage in problems such as inverse inference
where the number of samples is very small.
