I fine-tuned an LLM to be C-3PO to test which training data format works best for persona injection [P]

Tested three formats: chat demos, first-person statements (“I am C-3PO…”), and synthetic Wikipedia-style docs. Same model, same LoRA config, 500 examples each.

First-person statements won on generalization, which I didn’t expect. The synthetic doc model was the weirdest result: it knew C-3PO was anxious but only expressed it 37% of the time. Knowing a trait vs feeling it are apparently different things in weight space.

Code and GitHub repo link are included inside!