Noise: A Flaw in Human Judgment

According to the authors, “measurement, in everyday life as in science, is the act of using an instrument to assign a value on a scale to an object or event” (52). Judgments are therefore measurements where the human mind is the instrument. These include, for example, determining how many years a prison sentence should be. Human judgments always involve a degree of error, which is made up of bias and noise. Standard deviation, the tool used to measure variability in statistics, can determine noise in judgments. To reduce harmful errors, individuals need to understand and quantify the errors of the experts making decisions.

Inherent to the concept of judgment is the idea that a decision of agreed-upon ethicalness can be reached, rather than some whimsical response determined by opinion or taste. However, matters of judgment occupy an uneasy middle zone between fact and opinion, defined by “the expectation of bounded disagreement” (56).

Judges are prone to disagree on difficult problems, rather than those of obvious morality. (Here, the authors begin to use the term “judge” to describe any decision-maker, and not just judges in the court of law). To prove this point, the authors urge the reader to evaluate a fictional CEO candidate on a scale of zero-to-100, according to the likelihood of their ability to keep their job after two years.