Overgeneralization

Overgeneralizing Ollie

“One bug in the garden? Clearly the whole planet is infested.”

What's the problem?

An overgeneralization states a claim more broadly than the evidence supports: "some" becomes "all," "this group" becomes "everyone," "here" becomes "everywhere," or "this time" becomes "always." Broad claims aren't automatically wrong; some evidence really does support them. Narrowing a claim isn't automatically better either; the right scope is the one the evidence supports. Hasty Harry is a close cousin, and the two often overlap. Harry asks whether there are enough representative cases; Ollie asks how far the claim reaches beyond them.

Context: A gym surveyed 300 of its morning members; 70% said they prefer quieter music.

✗ Stretched

Every member of this gym prefers quieter music.

✓ Scoped to the evidence

70% of the 300 morning members surveyed preferred quieter music.

Why it works

The evidence covers 70% of the morning members surveyed, not every member. The revision reports the finding at the scope it was gathered and says nothing about evening members.