The objective of this study is to determine whether tracking people's streak of behavior increases their engagement in that behavior. To test this, the investigators are designing a web application that participants can access daily using their phones or computers. Our previous work suggests that streaks may be useful in motivating people to be more productive. In this study, the investigators change how the investigators operationalize streaks and test streaks in a field context. Because most previous streak research is on how others perceive someone who has a streak, this work is novel because it examines how encouraging someone to achieve and keep a streak affects behavior in a field context. The study will test two interventions for increasing engagement with a target behavior, delivered via a digital web application that participants can access using their phones or computers. For example, in the streak group, users would see how many consecutive days they have completed daily lessons and will be encouraged to extend their streak. In the tally group, participants will see how many cumulative days they have completed daily lessons and will be encouraged to extend their tally. The investigators are interested in whether people complete more daily lessons when a 30-day health challenge app provides daily feedback on their consecutive lessons (each comprising two multiple-choice questions) completed (i.e., "streaks") vs. when it provides feedback on their cumulative lessons completed (i.e., "tallies").
