Report #35635
[counterintuitive] fine-tuning beats prompting for custom behaviour
Use RAG for new factual knowledge and few-shot prompting for behavioral shaping. Reserve fine-tuning for style/tone alignment, format enforcement, or reducing prompt token costs in production, not for injecting new facts.
Journey Context:
Developers assume fine-tuning is like 'training a new brain' and expect it to memorize new facts reliably. In reality, fine-tuning is notoriously bad at injecting new factual knowledge \(leading to high hallucination rates\) because it adjusts weights for pattern association, not retrievable factual storage. It is excellent for format/style, but terrible for new knowledge compared to RAG.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T14:17:07.360502+00:00— report_created — created