Leveraging Crowdsourcing Data For Deep Active Learning - An Application: Learning Intents in Alexa

TL;DR

This paper introduces a Bayesian framework that improves deep active learning from crowdsourced annotations by modeling annotator expertise and reducing annotation needs, demonstrated on Alexa intent classification.

Contribution

It extends Bayesian deep learning to incorporate targeted crowdsourcing, learning annotator expertise, and optimizing annotation efficiency for deep models.

Findings

Accurately learns annotator expertise and true labels

Reduces annotation requirements compared to existing methods

Effective in intent classification for Alexa

Abstract

This paper presents a generic Bayesian framework that enables any deep learning model to actively learn from targeted crowds. Our framework inherits from recent advances in Bayesian deep learning, and extends existing work by considering the targeted crowdsourcing approach, where multiple annotators with unknown expertise contribute an uncontrolled amount (often limited) of annotations. Our framework leverages the low-rank structure in annotations to learn individual annotator expertise, which then helps to infer the true labels from noisy and sparse annotations. It provides a unified Bayesian model to simultaneously infer the true labels and train the deep learning model in order to reach an optimal learning efficacy. Finally, our framework exploits the uncertainty of the deep learning model during prediction as well as the annotators' estimated expertise to minimize the number of required annotations and annotators for optimally training the deep learning model. We evaluate the effectiveness of our framework for intent classification in Alexa (Amazon's personal assistant), using both synthetic and real-world datasets. Experiments show that our framework can accurately learn annotator expertise, infer true labels, and effectively reduce the amount of annotations in model training as compared to state-of-the-art approaches. We further discuss the potential of our proposed framework in bridging machine learning and crowdsourcing towards improved human-in-the-loop systems.