User Interaction and Response Measures
depression
Objective and subjective measures of user interaction included the number of voice-based conversational breakdowns during each session and self-administered surveys of workload, user experience, and the treatment alliance between the participant and Lumen after each session.A conversational breakdown was defined as instances where a participant’s voice input or response could not be interpreted by Lumen. Such conversational breakdowns resulted in the participant having to repeat or correct their response to move on to the next part of their coaching session. Conversational breakdowns could occur due to a variety of reasons including incorrect invocation (ie, a participant says an incorrect phrase), incomplete invocation (ie, a participant says an incomplete phrase in response to Lumen), incomprehensible invocation (ie, a participant says something Alexa could not understand), repeated invocation (ie, a participant repeats the same answer multiple times), and internet issues (ie, the participant has network issues leading to his or her voice input not being received). For ascertaining such conversational breakdowns with Lumen on the Alexa platform, we extracted participant conversations with the Lumen Alexa skill in a text format and coded all the instances of breakdowns (based on the aforementioned reasons) and computed counts of such breakdowns per user session.Workload was measured with a modified version of the National Aeronautics and Space Administration (NASA) Task Load Index (TLX) [The user experience was measured with the 10-item User Experience Questionnaire Short Version (UEQ-S) [The treatment alliance was measured with the 36-item Working Alliance Inventory-Technology Version (WAI-Tech) [A total of 2 response measures—PHQ-9 and GAD-7—were self-reported before each Lumen session. The PHQ-9 measures depression symptoms, with a score ranging between 0 (best) and 27 (worst) [