TreeCare: Development and Evaluation of a Persuasive Mobile Game for Promoting Physical Activity

Increased physical activity has been shown to reduce morbidity and mortality among adults. Over the years, mobile apps have been developed to encourage people to engage in physical activity, such as walking or running, by employing various persuasive strategies. However, the choice of these strategies is often based on designers' intuition without knowing if the strategies will be effective for target audience and the target behaviour. To address this gap, we conduct a study with 103 adults to assess the perceived effectiveness of 12 widely used strategies in health games design. The strategies are based on the Persuasive Systems Design (PSD) framework. Our results reveal that the strategies are effective for promoting physical activity at varying degrees. These results inform the development of the game, called TreeCare. Next, we conduct a 3-week field study involving 23 target users to evaluate the game in terms of effectiveness and usability. Our results show that TreeCare significantly improved users' physical activity levels. In addition, the game is found to be easy to use, engaging, aesthetically pleasing, and enjoyable. We reflect on our findings and offer practical guidelines to inform the design of effective and usable persuasive applications.