Klim Efremenko

Senior Academic

Non-parametric Binary regression in metric spaces with KL loss.

Ariel Avital, Klim Efremenko,Aryeh Kontorovich, David Toplin, Bo Waggoner
We propose a non-parametric variant of binary regression, where the hypothesis is regularized to be a Lipschitz function taking a metric space to [0, 1] and the loss is logarithmic. This setting presents novel computational and statistical challenges. On the computational front, we derive a novel efficient optimization algorithm based on interior point methods; an attractive feature is that it is parameter-free (i.e., does not require tuning an update step size). On the statistical front, the unbounded loss function presents a problem for classic generalization bounds, based on covering-number and Rademacher techniques. We get around this challenge via an adaptive truncation approach, and also present a lower bound
indicating that the truncation is, in some sense, necessary.
Publication language English
Publication status Published - 19.10.2020