A Dialogue-Based Interface for Active Learning of Activities of Daily Living

While Human Activity Recognition (HAR) systems may benefit from Active Learning (AL) by allowing users to self-annotate their Activities of Daily Living (ADLs), many proposed methods for collecting such annotations are for short-term data collection campaigns for specific datasets. We present a reusable dialogue-based approach to user interaction for active learning in HAR systems, which utilises a dataset of natural language descriptions of common activities (which we make publicly available) and semantic similarity measures. Our approach involves system-initiated dialogue, including follow-up questions to reduce ambiguity in user responses where appropriate. We apply our work to an existing CASAS dataset in an active learning scenario, to demonstrate our work in context, in which a natural language interface provides knowledge that can help interpret other multi-modal sensor data. We provide results highlighting the potential of our dialogue- and semantic similarity-based approach. We evaluate our work: (i) technically, as an effective way to seek users' input for active learning of ADLs; and (ii) qualitatively, through a user study in which users were asked to use our approach and an established method, and to subsequently compare the two. Results show the potential of our approach as a user-friendly mechanism for annotation of sensor data as part of an active learning system.