Unsupervised Domain Adaptation Based on the Predictive Uncertainty of Models

TL;DR

This paper introduces MUDA, a novel unsupervised domain adaptation method that uses model uncertainty within a Bayesian framework to better align source and target domains, outperforming existing methods.

Contribution

The paper proposes a new UDA approach leveraging model uncertainty as a divergence measure, extending it to multi-source domain adaptation, and demonstrating superior empirical performance.

Findings

MUDA outperforms state-of-the-art methods in image recognition tasks.

Model uncertainty effectively measures domain divergence.

Extension to multi-source adaptation is successful.

Abstract

Unsupervised domain adaptation (UDA) aims to improve the prediction performance in the target domain under distribution shifts from the source domain. The key principle of UDA is to minimize the divergence between the source and the target domains. To follow this principle, many methods employ a domain discriminator to match the feature distributions. Some recent methods evaluate the discrepancy between two predictions on target samples to detect those that deviate from the source distribution. However, their performance is limited because they either match the marginal distributions or measure the divergence conservatively. In this paper, we present a novel UDA method that learns domain-invariant features that minimize the domain divergence. We propose model uncertainty as a measure of the domain divergence. Our UDA method based on model uncertainty (MUDA) adopts a Bayesian framework and provides an efficient way to evaluate model uncertainty by means of Monte Carlo dropout sampling. Empirical results on image recognition tasks show that our method is superior to existing state-of-the-art methods. We also extend MUDA to multi-source domain adaptation problems.