Test sets

A test set is the ground truth for a training run. After fine-tuning, Luna Studio scores the resulting metric against the test set and reports F1, AUC-ROC, and other performance KPIs.

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What makes a good test set

• Human-labelled. Don’t auto-generate test labels — they’re the tape measure for evaluating the run.
• Representative of production data. Sample inputs from the same distribution your application sees in production.
• Size. Luna Studio enforces at least 300 rows total and 100 rows per label. Aim for 1,000-3,000 representative rows when possible.

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Required schema

Check Prerequisites for the columns required by each metric shape.

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File formats

• CSV — the end-to-end format for run validation and evaluation. Headers are required.
• JSONL — accepted by the source picker during ingestion, but current downstream processing reads CSV. Convert it to CSV before selecting it for a run.

Browser uploads are limited to 20 MiB.

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Add a test set

You can add a test set in three places:

• The Datasets page → Add test set primary button.
• The Step 2 of the run creation flow → dropdown’s Add new test set action.
• (Indirectly) by importing from Galileo — see Galileo integration.

All three paths open the same Add test set modal — see Add a dataset for the modal reference.

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Where to go next