Cognitive Biases

CogBias

A practical cognitive-bias site with clear definitions, learning paths, assessments, self-audits, and debiasing tools.

Learning Path

Decision Under Uncertainty

Biases that quietly bend choice, forecasting, escalation, and project planning when the future is still unresolved.

9 biases Foundational 50 min

By the end of this path

  • See how anchors, overconfidence, and inside-view planning bend forecasts before execution begins.
  • Practice switching from the inside story to the outside view.
  • Build better habits for ranges, reference classes, and stopping rules.

How to study it

Work the pages in order, then loop back and compare which distortions happened earliest, which ones protected the first impression, and which ones interfered with later learning.

Next:

Biases in this path

This is a deliberate sequence, not just a themed pile. Start at the top if the context is new to you.

Poster illustration for Anchoring effect

Anchoring effect

The tendency for the first salient number, frame, or option to pull later estimates toward itself even when it is arbitrary or weakly relevant.

EstimationBaselineForecasting & planningPersonal decisions
Poster illustration for Overconfidence effect

Overconfidence effect

The tendency to be more certain about judgments, forecasts, or abilities than the evidence warrants.

Hypothesis AssessmentOutcomeForecasting & planningTeams & management
Poster illustration for Gambler's fallacy

Gambler's fallacy

The tendency to think that future probabilities are altered by past events, when in reality they are unchanged.

EstimationBaseline
Poster illustration for Clustering illusion

Clustering illusion

The tendency to overestimate the importance of small runs, streaks, or clusters in large samples of random data.

Hypothesis AssessmentOutcome
Poster illustration for Planning fallacy

Planning fallacy

The tendency for people to underestimate the time it will take them to complete a given task.

EstimationOutcome
Poster illustration for Status quo bias

Status quo bias

The tendency to prefer the current option, default, or inherited arrangement simply because it is the current option, default, or inherited arrangement.

DecisionInertiaPersonal decisionsTeams & management
Poster illustration for Sunk cost effect

Sunk cost effect

The tendency to keep investing in a losing path because of what has already been spent, even when the forward-looking case has weakened.

DecisionInertiaPersonal decisionsTeams & management
Poster illustration for Outcome bias

Outcome bias

The tendency to judge a decision mainly by its result rather than by the quality of the reasoning behind it.

EstimationOutcomePostmortems & learningTeams & management
Poster illustration for Hindsight bias

Hindsight bias

The tendency after an outcome is known, to see it as having been more obvious or predictable than it actually was beforehand.

RecallOutcomePostmortems & learningForecasting & planning