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Governance & Risk

Constitutional AI

Constitutional AI (CAI) is a training technique, introduced by Anthropic in 2022, in which a model critiques and revises its own outputs against a written set of principles, then learns from those revisions instead of from human-labeled preferences alone.

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Full definition

CAI has two phases: (1) Supervised — the model generates responses, critiques them against the constitution, revises them, and is fine-tuned on the revisions; (2) RL from AI Feedback (RLAIF) — a preference model trained on AI-generated comparisons drives a PPO loop. In the 2022 paper the constitution was a short list of natural-language principles chosen for research; the version Anthropic published for Claude in May 2023 drew on the UN Declaration of Human Rights, platform guidelines such as Apple's terms of service, other labs' principles and Anthropic's own early research. In January 2026 Anthropic replaced that list with a long-form constitution that explains the reasoning behind Claude's values. CAI scales oversight by reducing the human-labeling bottleneck.

Why it matters

CAI is the most prominent example of scalable oversight — using AI to help align AI. For buyers, it means model behavior can be steered by editing a written document rather than relabeling thousands of examples, which is materially cheaper and more auditable.

Example

Anthropic publishes Claude's constitution (CC0); an enterprise customer can read it, compare its priorities with their own domain policies, and use it to interpret why the model refuses or complies.

Next steps

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Source & further reading

Primary source: Bai et al. — "Constitutional AI: Harmlessness from AI Feedback" (Anthropic) (2022).

Citation policy: this entry is part of the AIDOLS AI Implementation Glossary and may be quoted for research, journalism, and education with attribution to aidolsgroup.com/en/glossary/constitutional-ai/.