Sahaj.blogs

Day page

4 Feb 2026

Study

LLMs · Instruction tuning

Supervised fine-tuning on instruction–response pairs turns a base model into an assistant; comparing SmolLM2-135M base and instruct on the same question, and masking the loss to the response.

  • A base model continues text; an instruction-tuned model answers it.
  • During SFT the loss is usually computed only on the response tokens, not on the prompt.

Read the post →