The Quantified Self is a movement that promotes the use of technology for self-tracking various kinds of personal information, such as physical activities and energy consumption. In this paper, we study the user reviews of quantified self tools, as reported on a quantified self community website. We perform a content analysis to categorize tracking tools, and to explore user experience (UX) issues related to quantified self technologies.
From this analysis, we find various tracking categories, including body state (e.g., physical and physiological), psychological state and traits, activities (e.g., exercise, eating, sleep), social interactions, and environmental and property states. Furthermore, we find the key UX issues associated with quantified self technologies, which include data controllability, data integration, data accuracy, data visualization, input complexity, sharing/privacy, design/aesthetics, and engagement. The UX issues reported in this paper have significant implications for the design of quantified self technologies.