Noise: A Flaw in Human Judgment

Noise examines why people make inconsistent judgments and how to improve decision-making. The book explores situations where identical cases produce different outcomes—such as two doctors diagnosing the same patient differently, two judges sentencing similar crimes with different severity, or interviewers at the same company making different hiring decisions about comparable applicants. Even the same person may judge differently depending on the time of day or day of the week. These variations represent noise: inconsistency in judgments that should be identical. Daniel Kahneman, Olivier Sibony, and Cass R. Sunstein demonstrate how noise affects numerous fields, including medicine, law, economic forecasting, forensic science, bail decisions, child protection, strategy, performance reviews, and hiring. While judgment exists in most professional and organizational contexts, noise often goes unrecognized. The authors present practical approaches to reduce both noise and bias, enabling better decision-making. The book combines original research with insights into why humans are susceptible to noise in judgment and what steps can address it.