Visualization of Time-Series Sensor Data to Inform the Design of Just-In-Time Adaptive Stress Interventions

Abstract

We investigate needs, challenges, and opportunities in visualizing time-series sensor data on stress to inform the design of just-in-time adaptive interventions (JITAIs). We identify seven key challenges: massive volume and variety of data, complexity in identifying stressors, scalability of space, multifaceted relationship between stress and time, a need for representation at multiple granularities, interperson variability, and limited understanding of JITAI design requirements due to its novelty. We propose four new visualizations based on one million minutes of sensor data (n=70). We evaluate our visualizations with stress researchers (n=6) to gain first insights into its usability and usefulness in JITAI design. Our results indicate that spatio-temporal visualizations help identify and explain between- and within-person variability in stress patterns and contextual visualizations enable decisions regarding the timing, content, and modality of intervention. Interestingly, a granular representation is considered informative but noise-prone; an abstract representation is the preferred starting point for designing JITAIs.

Keywords: Just-in-time Adaptive Interventions (JITAIs); Stress; Stress Management; Visualization.

Figures

Figure 1

Participant stress profile. Circles and edges represent locations and transitions between them. The size of a circle is proportional to the time spent at a location and the width of the edge is proportional to the number of transitions between nodes. Color represents stress intensity (green = negligible, lime-green = low, yellow = moderate, orange = high, red = extremely high).

Figure 2

Figure 2(a). Temporal stress profile of participant P4. Each bar represents stress for a day. X-axis and Y-axis represent time-of-day and days-of-the-week respectively. Colors represent stress intensity (red = high stress, green = low stress, yellow = moderate stress, grey = unknown) Figure 2(b). Temporal stress profiles of four participants. Colors represent stress intensity (red = high stress, green = low stress, yellow = moderate stress, grey = unknown). Each bar represents a day’s stress data, which are grouped by participants.

Figure 2

Figure 2(a). Temporal stress profile of participant P4. Each bar represents stress for a day. X-axis and Y-axis represent time-of-day and days-of-the-week respectively. Colors represent stress intensity (red = high stress, green = low stress, yellow = moderate stress, grey = unknown) Figure 2(b). Temporal stress profiles of four participants. Colors represent stress intensity (red = high stress, green = low stress, yellow = moderate stress, grey = unknown). Each bar represents a day’s stress data, which are grouped by participants.

Figure 3

Contextual stress profile of a participant. X-axis shows time, Y-axis shows stress level and context (activity and location). Black dashed line represents baseline stress.

Figure 4

Event-based stress profile of a participant. X-axis shows days and y-axis shows time-of-the-day. Size represents number of smoking episodes and color represents associated stress level. Icons are used to represent location ( = home, = work, = other location than home and work).