Precision bias

Precision bias is a form of cognitive bias in which an evaluator of information commits a logical fallacy as the result of confusing accuracy and precision. More particularly, in assessing the merits of an argument, a measurement, or a report, an observer or assessor falls prey to precision bias when they believe that greater precision implies greater accuracy (i.e., that simply because a statement is precise, it is also true).

In a decision-making context, precise information is perceived to be more accurate, weighted more heavily when forming judgements, and influences which sources of advice people seek out. The concept is also applied in reverse: advisors may use more precise figures than are warranted in order to elicit unwarranted confidence in a claim, known as false precision. The bias has been observed to affect judgement across many real-world contexts, including negotiation, legal adjudication, and medical communication.