Ho, Bo-JhangNikzad, NimaBalaji, BharathanSrivastava, Mani2020-06-082020-06-080000-00-00http://dx.doi.org/10.1145/3123024.3124568https://lib.digitalsquare.io/handle/123456789/62300Mobile technologies that drive just in time ecological momentary assessments and interventions provide an unprecedented view into user behaviors and opportunities to manage chronic conditions The success of these methods rely on engaging the user at the appropriate moment so as to maximize questionnaire and task completion rates However mobile operating systems provide little support to precisely specify the contextual conditions in which to notify and engage the user and study designers often lack the expertise to build context aware software themselves To address this problem we have developed Emu a framework that eases the development of context aware study applications by providing a concise and powerful interface for specifying temporal and contextual constraints for task notifications In this paper we present the design of the Emu API and demonstrate its use in capturing a range of scenarios common to smartphone based study applications