Effective Visualization of Long Term Health Data to Support Behavior Change

The reflective stage, which is crucial for behavior change, can be facilitated with suitable visualizations that allow users to answer specific questions with regard to their health data. To date, effective visualizations which combine time series data and the appraisal of this data in one chart are, however, rare. To close this gap in research, twenty participants compared two alternative long-term visualizations of health behavior: an accumulated bar chart and a point chart which both include appraisals of the underlying health data based on current recommendations of leading health organizations, such as the World Health Organization or the European Food Information Council. Participants answered three types of question (progress over time, correlations between different health behaviors, and health consciousness). The sequence of visualization for the underlying data sets was cross balanced over participants. The accumulated bar chart resulted in more trials in which participants were unable to answer. In some cases, this type of visualization also resulted in biased interpretations with regard to progress over time and health consciousness. Summarizing, we recommend the point chart, in which the background is colored according to the recommendation of the respective health behavior. Both types of visualization are, however, not optimal for the identification of correlations.