What Data is Claude Trained On? [2023]

Claude is an artificial intelligence chatbot created by Anthropic to be helpful, harmless, and honest. It is trained on a diverse dataset of natural language conversations in order to have nuanced and informed dialogues across a wide range of topics.

Unlike other chatbots that are trained on narrow domains or scraped data from the internet, Claude’s training data is carefully curated to model human values and reasoning. The goal is for Claude to engage in open-domain conversations and provide useful information to users.

Data Sources on which Claude Trained

The training data for Claude comes from a variety of sources, all with the aim of exposing the model to high-quality natural language:


A key source of Claude’s training data is self-dialogue, where humans have unstructured conversations with themselves on a diverse range of topics. Professional writers are employed to chat naturally about their lives, experiences, and random thoughts. This produces very human-like conversational data.

Expert Demonstrations

Domain experts across different fields like science, history and current affairs are engaged to discuss topics in their expertise. This gives Claude grounding in factual knowledge across disciplines. The experts ensure high quality, nuanced dialogue is used.

Synthetic Dialogue

Synthetic conversational data is generated algorithmically to augment the human self-dialogue. This expands the diversity of training data and builds inconsistency tolerance. The synthetic data uses clausal variations, paraphrasing, co-reference and other natural language techniques.

Books & Wikipedia

Public domain books provide a rich source of knowledge for Claude, exposing it to a wide range of topics and writing styles. Wikipedia articles are included as a knowledge source on facts about the world. Both sources are used to train Claude’s ability to discuss topics meaningfully.

Crowdsourced Feedback

As Claude interacts with real users, their feedback is incorporated into the training to continually improve Claude’s abilities. User ratings on the quality and safety of its responses provides human guidance for the model.

Data Collection Process

Anthropic has built custom tooling and interfaces to efficiently collect high-quality training data for Claude:

Self-Chat Tool

This is a conversational interface where human writers can chat naturally with themselves across a diverse range of personal and impersonal topics. Guidance is provided on topics to cover.

Expert Chat Tool

A similar tool for domain experts to discuss topics in their field of expertise. This produces engaging, factual conversations grounded in knowledge.

Synthetic Dialogue Engine

An engine that uses advanced natural language techniques like paraphrasing, co-reference and variation to automatically generate billions of high-quality synthetic conversations.

Data Review Tool

Human reviewers use this tool to validate data quality, annotate conversational attributes, and provide safety/quality ratings. This ensures only appropriate high-quality data is used for training.

Crowdsourcing Platform

A platform to collect ratings and feedback on Claude’s responses from real users. This continuously provides new data to improve Claude’s abilities.

Training Approach

Training Claude requires a multi-stage approach focused on safety, quality and robustness:

Self-Supervised Pretraining

In the first stage Claude is trained in a self-supervised manner on the diverse conversational datasets through prediction tasks. This builds broad linguistic and conversational competency.

Human-in-the-Loop Training

Next, Claude is trained with human reviewers and users in the loop, getting supervised feedback and validation to align its responses to human preferences. This tunes Claude’s performance.

Ongoing Feedback Integration

Finally, once deployed, Claude continues training as it interacts with users. Ratings and preferences are incorporated into the model to keep improving it.

Data Safety & Control

Multiple measures are taken to ensure responsible and controlled use of training data:

Consent & Privacy Protection

All data sources only use publicly available data or data from consenting participants. No private data is collected without permission. Personal information is anonymized.

Harmful Data Avoidance

Data collection explicitly avoids toxic, illegal, dangerous or unethical content. Data is screened to filter out any harmful examples.

Bias & Stereotype Mitigation

Analysis is done to measure bias and stereotypes in the data. Problematic data is corrected to mitigate issues through data balancing and filtering.

Access Control & Auditing

Strict access controls are implemented for who can view, modify and use the training data. Auditing provides transparency into how the data is used.

External Oversight

Anthropic collaborates with external researchers and auditors to regularly review data practices and identify improvement opportunities. This ensures high standards.


Claude’s training data is carefully designed to produce an AI assistant that is helpful, harmless, and honest. A diverse range of high-quality conversational data teaches Claude to have nuanced, knowledgeable dialogues.

Rigorous controls and processes ensure responsible data practices focused on user benefits rather than exploiting users. With a foundation of ethical AI, Claude aims to have sophisticated conversations that improve people’s lives.


What are the main sources of training data for Claude?

The key sources of training data for Claude include self-dialogue from professional writers, expert demonstrations, synthetic dialogue, books, Wikipedia, and crowdsourced feedback from users. This diverse data helps Claude conduct nuanced conversations across a wide range of topics.

How is the self-dialogue training data produced?

Professional writers have natural conversations with themselves about their lives, experiences, and thoughts using a custom self-chat tool. This produces very human-like conversational data to train Claude. Guidance is provided on topics to cover in the self-chat.

Why are domain experts included in the training process?

Experts in fields like science, history and current affairs discuss topics in their expertise using a custom tool. This exposes Claude to high-quality, factual conversations grounded in specialized knowledge across disciplines.

What methods are used to generate synthetic training conversations?

An engine uses advanced natural language techniques like paraphrasing, co-reference, and variation to algorithmically produce billions of synthetic conversational examples. This increases training data diversity.

How is the quality of training data ensured?

Human reviewers validate data using a specialized tool, annotating attributes and providing safety/quality ratings. Only appropriate high-quality data that meets standards is used for Claude’s training.

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