Tag: sft

All the articles with the tag "sft".

• Fine-Tuning, and What It Destroys

  Updated:16 Oct, 2026

  Fine-tuning moves a pretrained model a short distance in weight space, and how far it moves decides what it gains and what it forgets. Continued pretraining vs supervised fine-tuning, the SFT loss with prompt masking worked on a real chat template, learning rates and memory. Then Qwen2.5-0.5B fine-tuned on this blog, two seeds per setting, with what it learns and what it forgets measured side by side; replay as the remedy, EWC derived, and when fine-tuning is the wrong tool.