Design frictions, a term found in popular media articles about user experience design, refer to points of difficulty occurring during interaction with technology. Such articles often argue that these frictions should be removed from interaction flows in order to reduce the risk of user frustration and disengagement. In this paper we argue that, in many scenarios, designing friction into interactions through the introduction of microboundaries, can, in fact, have positive effects. Design frictions can disrupt "mindless" automatic interactions, prompting moments of reflection and more "mindful" interaction. The potential advantages of intentionally introduced frictions are numerous: from reducing the likelihood of errors in data-entry tasks, to supporting health-behaviour change.

Habit formation is an important part of behavior change interventions: to ensure an intervention has long-term effects, the new behavior has to turn into a habit and become automatic. Smartphone apps could help with this process by supporting habit formation. To better understand how, we conducted a 4-week study exploring the influence of different types of cues and positive reinforcement on habit formation and reviewed the functionality of 115 habit formation apps. We discovered that relying on reminders supported repetition but hindered habit development, while the use of event-based cues led to increased automaticity; positive reinforcement was ineffective. The functionality review revealed that existing apps focus on self-tracking and reminders, and do not support event-based cues. We argue that apps, and technology-based interventions in general, have the potential to provide real habit support, and present design guidelines for interventions that could support habit formation through contextual cues and implementation intentions.

Research Methods for Human-Computer Interaction - August 2008