Timezone: »

Contrastive Learning from Pairwise Measurements
Yi Chen · Zhuoran Yang · Yuchen Xie · Zhaoran Wang

Thu Dec 06 02:00 PM -- 04:00 PM (PST) @ Room 210 #70

Learning from pairwise measurements naturally arises from many applications, such as rank aggregation, ordinal embedding, and crowdsourcing. However, most existing models and algorithms are susceptible to potential model misspecification. In this paper, we study a semiparametric model where the pairwise measurements follow a natural exponential family distribution with an unknown base measure. Such a semiparametric model includes various popular parametric models, such as the Bradley-Terry-Luce model and the paired cardinal model, as special cases. To estimate this semiparametric model without specifying the base measure, we propose a data augmentation technique to create virtual examples, which enables us to define a contrastive estimator. In particular, we prove that such a contrastive estimator is invariant to model misspecification within the natural exponential family, and moreover, attains the optimal statistical rate of convergence up to a logarithmic factor. We provide numerical experiments to corroborate our theory.

Author Information

Yi Chen (Northwestern University)
Zhuoran Yang (Princeton University)
Yuchen Xie (Northwestern University)
Zhaoran Wang (Princeton, Phd student)

More from the Same Authors