Hasty generalization
Also called: Jumping to a conclusion
Drawing a broad conclusion from too few or unrepresentative examples.
How to spot it
How many cases is the conclusion based on, and how were they picked?
Example
“I met two rude people from that city. Everyone there is rude.”
How to answer it
Ask how big and how fair the sample was.
Related
- Anecdotal evidence: Using one person's story as if it settled a general question.
- Cherry-picking: Showing only the evidence that supports your case, and leaving out the rest.