Designing for Self-awareness: Evidence-Based Explorations of Multimodal Stress-Tracking Wearables

Early wearable devices using multimodal data to promote stress-awareness are emerging on the consumer market. They prove to be effective tools to support users in tracking their daily activities, yet their potential still needs to be further explored. From a user experience design perspective, such wearable devices could help users understand how they feel stress and ultimately shed light on its psychophysiological bases. Based on this rationale, this paper reports the results of evidence-based explorations aimed at formalizing knowledge regarding the use of multimodal stress-tracking wearables. Following a human-centered design process, we design an interactive prototype that tracks two stress-related parameters, namely physiological and perceived stress. We employ a smartwatch to track blood volume pulse and heart rate variability to assess physiological stress, whereas we rely on self-reports gathered through a smartphone to assess perceived stress. We then test the prototype in a controlled setting with 16 end-users. Tests combine qualitative and quantitative research methods, including in-depth interviews, eye-tracking, and surveys encompassing a Kano model-based and AttrakDiff questionnaires. In-depth interviews reveal insights about the type and quantity of information users expect. Ocular scanpaths provide directions to leverage the cognitive effort required by users when interacting with multiple devices. Lastly, evidence from surveys highlights the features and functions that multimodal stress-tracking apps should include. Based on our findings, we create a set of considerations on personal informatics promoting stress awareness from a user experience design perspective. Lastly, we outline future directions for the research design of wearable solutions to promote self-awareness.