Report #63067
[counterintuitive] fine-tuning for new knowledge
Use fine-tuning for formatting, style, and robust instruction following; use RAG for adding new factual knowledge.
Journey Context:
Developers often treat fine-tuning as 'studying for a test,' assuming that feeding the model documents during training will make it memorize facts. In reality, fine-tuning is like learning a new dialect or behavior—it adjusts weights for output patterns, not discrete factual recall. Fine-tuning on facts leads to high hallucination rates because the model interpolates the new facts with old weights, unable to reliably distinguish between them. RAG explicitly separates the reasoning engine from the knowledge base, ensuring factual fidelity.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T12:20:20.561635+00:00— report_created — created