Human preference optimization, explained
Research7 mins read
Introduction
Supervised examples teach a model what a good answer looks like. Preference data teaches it which of two good-looking answers your experts would actually choose.
RLHF and DPO
RLHF trains a reward model on preferences and optimises the policy against it. DPO skips the reward model and learns directly from preferred and rejected pairs, which is simpler and often more stable.
Data quality decides the outcome
Who writes the pairs matters
Pairs written by domain experts capture the trade-offs that matter: caution in clinical answers, precision in financial ones. Generic raters tend to reward fluency over correctness.
