Report #90136
[counterintuitive] Fine-tuning LLMs to inject new factual knowledge
Use RAG for new facts; reserve fine-tuning for shaping output format, tone, or behavioral patterns.
Journey Context:
Developers treat fine-tuning as 'saving data into the model's brain.' However, LLMs are pattern matchers, not databases. Fine-tuning on raw facts leads to high hallucination rates because the model learns to approximate the distribution of the text rather than memorizing exact key-value pairs. RAG explicitly provides the facts at inference, separating retrieval from generation.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T09:53:19.327565+00:00— report_created — created