Types of AI training data
Choose between demonstrations, preferences, rubrics, trajectories and adversarial examples.
4 min readThe right data format depends on the behaviour you are trying to create or measure. Selecting a familiar format without defining that behaviour first creates expensive, low-signal data.
Demonstrations
High-quality input-output examples show the model what a good response looks like. They work best when contributors can explain the standard and cover meaningful variation.
Preferences and critiques
Pairwise rankings reveal which of two outputs better meets the goal. Critiques add diagnostic value by explaining the error and what should change.
Evaluations and trajectories
Rubric evaluations measure behaviour without necessarily training on the answer. For agents, step-by-step trajectories reveal planning, tool selection, recovery and completion failures.
- Gold and calibration items
- Safety red-team prompts
- Tool-use traces
- Outcome verification
- Expert adjudication
Corrections and structured error labels
A corrected response shows both the failure and a better alternative. Structured error labels make the dataset easier to analyse: teams can distinguish factual errors, missing constraints, unsafe advice, weak tool use and style problems instead of treating every rejection as equivalent.
Synthetic data and human verification
Synthetic examples can expand coverage and create rare scenarios quickly, but they inherit the generating model's assumptions and mistakes. Use humans to validate realism, remove duplicates, check specialist facts and confirm that generated cases represent the target population.
Match the format to the learning objective
Demonstrations are useful when a clear ideal output exists. Preferences help optimise relative quality. Critiques explain failure modes, while evaluations measure a system without necessarily training it. Agent trajectories are needed when the path—planning, tools and recovery—matters alongside the final answer.
- Define the behaviour before choosing a format
- Collect the minimum fields needed for that behaviour
- Keep evaluation data separate from training data
- Version schemas and instructions together
- Measure downstream effect before scaling collection
Plan a balanced dataset
A balanced set reflects meaningful variation in users, tasks, difficulty, language and risk—not necessarily equal counts in every category. Oversample rare, consequential failures for learning while preserving a representative evaluation set for honest measurement.