Opportunities and Challenges for Long-Term Tracking

As self-tracking has evolved from a niche practice to a mass-market phenomenon, it has become possible to track a broad range of activities and vital parameters over years and decades. This creates both new opportunities for long term research and also illustrates some challenges associated with longitudinal research. We establish characteristics of very long-term tracking, based on previous work from diverse areas of Ubicomp, HCI, and health informatics. We identify differences between long- and short-term tracking, and discuss consequences on the tracking process. A model for long-term tracking integrates the specific characteristics and facilitates identifying viewpoints of tracking. Finally, a research agenda suggests major topics for future work, including respecting gaps in data and incorporating secondary data sources.