In this presentation, Dr. Klasnja will describe how micro-randomized trials can be used to make data-driven decisions about how exactly individual components of mHealth interventions should work to optimize their effectiveness. He will argue that a key value of micro-randomized trials during intervention development is their ability to generate data for informing decisions about the many specifics—from the design of the interface to the adaptation algorithms—that must be determined to implement an mHealth intervention. Data from micro-randomized trials enable such decisions to be made in ways that maximize intervention effectiveness while minimizing user burden.