Noise: A Flaw in Human Judgment

by Daniel Kahneman

Some judgments are biased; they are systematically off target. Other judgments are noisy, as people who are expected to agree end up at very different points around the target. Many organizations, unfortunately, are afflicted by both bias and noise.

A general property of noise is that you can recognize and measure it while knowing nothing about the target or bias.

Personnel decisions are noisy. Interviewers of job candidates make widely different assessments of the same people. Performance ratings of the same employees are also highly variable and depend more on the person doing the assessment than on the performance being assessed.

Occasion noise is the variability in judgments of the same case by the same person or group on different occasions. A surprising amount of occasion noise arises in group discussion because of seemingly irrelevant factors, such as who speaks first.

decision hygiene.

noise can produce large economic losses.

large number of people making a large number of judgments.

the sheer volume of noise presented an expensive problem.