Report #91694
[counterintuitive] Is fine-tuning always better than prompting for custom behavior
Exhaust prompt engineering \(including few-shot and RAG\) before fine-tuning; use fine-tuning primarily for style, format, or cost reduction, not for injecting new factual knowledge.
Journey Context:
Developers often jump to fine-tuning to 'teach' the model new facts or complex behaviors. Fine-tuning is actually quite poor at injecting new knowledge \(it just adjusts weights to favor certain outputs, leading to high hallucination rates for new facts\) but excellent at shaping the distribution of outputs \(style, format\). Prompting and RAG are far superior for grounding the model in new facts or complex, dynamic instructions.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T12:29:57.186008+00:00— report_created — created