Decision Theory Foundations

11 canonical decision-theory primitives for decisions under uncertainty. Each primitive is a formal tool with defined inputs, outputs, and failure modes. Primitives are domain-agnostic: the same expected-utility calculation that gates a product launch gates a capital investment; the same EVPI formula that sizes a market research study sizes a pre-launch pilot.

When to Apply

Apply decision-theory when:

• Single irreversible call under uncertainty (launch / kill / restructure)
• Value-of-information question — "is the next experiment worth running?"
• Real-options framing — staged investment with kill criteria
• Multi-criteria choice with explicit weights (MCDA, AHP)
• Multi-armed bandit allocation between treatments under regret minimisation