Probabilistic Dialogue Modeling for Speech-Enabled Assistive Technology
William Ho Cheung Li, Jim Glass, Nicholas Roy, Seth J. Teller · 2013
People with motor disabilities often face substantial challenges using interfaces designed for manual interaction. Although such obstacles might be partially alleviated by automatic speech recognition, these individuals may also have cooccurring speech-language challenges that result in high recognition error rates. In this paper, we investigate how augmenting speech applications with dialogue interaction can improve system performance among such users. We construct an end-to-end spoken dialogue system for our target users, adult wheelchair users with multiple sclerosis and other progressive neurological conditions in a specialized-care residence, to access information and communication services through speech. We use boosting to discriminatively learn meaningful confidence scores and ask confirmation questions within a partially observable Markov decision process (POMDP) framework. Among our target users, the POMDP dialogue manager significantly increased the number of successfully completed dialogues (out of 20 dialogue tasks) compared to a baseline threshold-based strategy (p = 0.02). The reduction in dialogue completion times was more pronounced among speakers with higher error rates, illustrating the benefits of probabilistic dialogue modeling for our target population. Index Terms: spoken dialogue systems, speech interfaces, POMDPs