There is an increasing trend in health behavior research to use mobile devices, such as smartphones to provide interventions. These methods - known as Ecological Momentary Interventions [EMI] - are innovative because they allow researchers and clinicians to offered information to people at specific times and in settings when they may be most in need of such support. One way EMI can be tailored is by having participants complete repeated self-report assessments on mobile devices such as smartphones (known as Ecological Momentary Assessment [EMA]), and then using this material to identify times when people are in need of intervention. Although some studies (including recent studies conducted by members of our research team) have developed interventions that use EMA to create real-time interventions that are delivered in daily life, to our knowledge no study has used objective ambulatory assessment data to do so. Using objective data is potentially advantageous because it utilizes passive data collection (requiring little or no input by participants), and thus reduces participant burden and potential concerns regarding accuracy of self-reported data.