ML: Active learning

Centroid-Halving Preference Queries

Use a convex uncertainty region over latent item scores to select the next ranked-list query, rather than training separate pairwise preference predictors. Sort the centroid of the current region to obtain a proper ranking; every returned pairwise counterexample intersects the region with a halfspace and removes a constant fraction of its volume under the centroid-cut guarantee. This provides an active-learning procedure for preference models, reward models, or ranking heads that remains…