hardScenarioDesignMidSeniorStaff
You have fine-tuned a model for a task. How do you prove it helped?
5 min readUpdated 2026-08-15
Answer
Short answer
Compare it against a genuinely strong prompted baseline on a held-out set drawn from real traffic, using the task metric your product cares about, and run a broad regression set alongside to catch capability lost elsewhere.
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Likely follow-ups
- Your held-out set was split randomly from the same export. What could that hide?
- The fine-tune wins by two points on 200 examples. Do you ship it?
- How would you detect that the fine-tune has degraded refusal behaviour?
- What would make you ship a fine-tune that scored slightly worse than the prompted baseline?
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