Bayesian Decision Lab

Make decisions under uncertainty using priors, signals, posterior beliefs, and expected utility.

Bayesian Decision under Uncertainty

Your payoff0
Posterior risk0%
Optimal-action matches0
Cases0
Ready.

How this teaches game theory

This lab shows how rational decisions depend on beliefs as well as payoffs. A signal updates prior probabilities through Bayes' rule, and the decision maker should choose the action with the highest expected utility rather than the action that would have been best after seeing the hidden state.

Complete scenario, mode, level, and concept guide

Scenarios

Weather-sensitive event

Choose an outdoor or indoor plan after receiving a weather forecast.

Cybersecurity investment

Choose whether to invest heavily or lightly after observing a risk signal.

Product launch

Choose a large or small launch after receiving imperfect market research.

Modes

Human decision maker

You interpret the signal and choose an action without a recommendation.

Human + recommendation

The computer displays the Bayesian expected-utility recommendation, but you still make the final choice.

Computer decision maker

The computer chooses the expected-utility-maximizing action automatically.

Levels

Level 1 — Clear signal

Signals are highly informative, so posterior beliefs move strongly.

Level 2 — Noisy signal

Signals are less reliable, making prior beliefs more important.

Level 3 — Costly information

Observing the signal incurs a cost, introducing the value-of-information question.

Observe: a good decision can still produce a bad realized outcome. Evaluate decisions by expected utility given the information available at the time.