Report #49482
[counterintuitive] Should I fine-tune an LLM to teach it new facts
Use RAG for adding new knowledge or facts; reserve fine-tuning for shaping output format, tone, and behavioral patterns.
Journey Context:
It is tempting to fine-tune a model on a corpus of documents so it 'learns' the information. However, fine-tuning is notoriously bad for knowledge injection. The model treats the new facts as weak associations rather than ground truth, leading to high hallucination rates when queried on those specific facts. Fine-tuning adjusts the model's distribution, making it behave like the data, but it cannot reliably recall the data.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T13:32:21.602836+00:00— report_created — created