Statistics and risk
Effect size
The magnitude of a difference, association or treatment effect.
What it means
Definition
Effect size. Effect size is central to judging whether a claim is proportionate. A study can identify a real association while the measured effect remains too small to justify a dramatic headline.
What it can tell you
It can help clarify what sort of evidence or claim is being discussed.
What it cannot tell you
It cannot, by itself, prove that the headline is accurate or clinically important.
Headline trap
Why this matters in headlines
deHype reports look for whether the article explains how big the effect actually was.