Overgeneralization

To draw a conclusion or make an inference about something — a conclusion or inference that goes beyond what one may justifiably conclude or infer based on the available evidence. For example, let's say that you observe a baseball team win the first ten games of the season and, based on these observations, you make the following generalization: the team will have a winning season. This generalization is justified by the observations you made (even though it may turn out to be wrong). On the other hand, you would be overgeneralizing if you inferred that the team will have a winning season next year, too: the observations cannot justifiably be used to predict what the team will do in a future season.

(See overextrapolation)
(See induction)