Noise: A Flaw in Human Judgment

by Daniel Kahneman

importance of sequencing information.

important not to be exposed to irrelevant information early in the judgment process.

one of the most important noise-reduction strategies: aggregating multiple independent judgments.

guaranteed to reduce noise.

judgment guidelines.

directly reduce between-judge variability in final judgments.

the critical importance of using a shared scale grounded in an outside view.

personnel selection,

illustrates the value of an essential decision hygiene strategy: structuring complex judgments. By structuring, we mean decomposing a judgment

general approach to option evaluation called the mediating assessments protocol, or MAP for short.

typical decision process for both recurring and singular decisions.

If the goal is to reduce noise, in practice, how many judgments should be aggregated?

Structuring judgments can be valuable, but exactly how valuable is it in different contexts?

decision maker should aspire to achieve a more precise understanding of the likely gains from each decision hygiene strategy—and of the corresponding costs,

how to identify these better judges.

both less noisy and less biased when those who make them are well trained, are more intelligent, and have the right cognitive style.

what you know, how well you think, and ...

tend to be actively open-minded and willing to learn fro...

how often they have been right in the past.

many judgments are not verifiable.

The confidence we have in these experts’ judgment is entirely based on the respect they enjoy from their peers. We call them respect-experts.

all these fields, and many more, the judgments of one professional can be compared only with those of her peers.

often value the opinion of respect-experts even when they disagree with one another.

You know that at least some of the analysts are wrong, because they are in disagreement. Yet you respect their expertise.

What makes a respect-expert?

existence of shared norms, or professional doctrine.

trained to use certain methods and follow certain norms.

doctrine does not fully specify how to proceed.

Experts still produce judgments, not computations.

experience is necessary, too.

respect-experts is their ability to make and explain their judgments with confidence.

confident people have more weight than others, even if they have no reason to be confident.

coherent stories.

recognize patterns, to reason...

They easily fit the facts they see into a coherent story that ...

How can we know which experts are likely to make good judgments?

Intelligence is correlated with good

performance in virtually all domains.

thousands of studies have measured the link between cognitive test scores and subsequent performance.

“GMA predicts both occupational level attained and performance within one’s chosen occupation and does so better than any other ability, trait, or disposition and better than job experience.”

Psychologists and neuroscientists distinguish between crystallized intelligence, the ability to solve problems by relying on a store of knowledge about the world (including arithmetical operations), and fluid intelligence, the ability to solve novel problems.

remains by far the best single predictor of important outcomes.

correlation of .50 indicates a very strong predictive value by social-science standards.

high mental ability is apparently a necessary condition for gaining access to high-status professions.

measure fails to capture differences in achievement within these groups.

GMA contributes significantly to the quality of performance in occupations that require judgment, even within a pool of high-ability individuals.

this line of reasoning has an important limitation.

Medieval astrologers must have been among the highest-GMA people of their time.

Do people with the best judgment have other recognizable traits?

cognitive style, or their approach to judgment tasks.