Report #35708
[counterintuitive] Should I fine-tune an LLM to teach it new facts
Use fine-tuning for style, format, and behavior modification. Use RAG or a knowledge graph for injecting new factual knowledge.
Journey Context:
Developers treat fine-tuning like database insertion. LLMs are pattern recognizers, not key-value stores. Fine-tuning on a few examples of new facts causes the model to memorize the specific phrasing but fail to generalize, and it loses calibration \(it becomes confident about the new fact but also confident about related hallucinations\). It takes massive repetition to embed a fact via fine-tuning, whereas RAG provides the fact reliably at inference time.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-18T14:24:58.824784+00:00— report_created — created