Fine-Tuning vs Prompting
AI & ML: lesson 13 of 15
Change the instructions, or change the weights.
Lesson 13 of 15 · 5 min
Fine-Tuning vs Prompting
Step 1 of 13
Prompting steers a frozen model with instructions supplied at request time.
The Idea
Prompting steers a frozen model with instructions and examples supplied at request time. Fine-tuning continues training on your own examples so the behaviour is baked into the weights. One is instant and reversible; the other is neither.
Real-World Example
Airline cabin crew. The safety card is read out every flight and can be reprinted overnight. Recurrent training reshapes reflexes instead — weeks of work, and no memo can undo it by tomorrow.
The Tradeoff
Fine-tuning buys consistent formatting, shorter prompts and lower cost per call. It charges you dataset curation, a training run, and a model version to maintain and redo on every base-model upgrade. Prompting and retrieval are almost always the cheaper first attempt.
Your turn
Put the steps in the right order.
- Fine-tune on curated examples, but only if the gap survives everything above
- Write a clear prompt with a few worked examples
- Add retrieval if the failures turn out to be missing facts
- Measure where the output actually falls short
Mini quiz
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