Experimental Configuration

iEpi is meant to be an experimental platform which is configured to address specific questions about a target population. In this way it is distinct from similar projects which harvest unstructured data from social networks, map queries or games. The purpose of iEpi is to harvest regular, repeated high fidelity information on target demographics who have been supplied with the app as part of a larger study.

Duty Cycles

Because the default iEpi configuration is for monitoring throughout the day, and smartphone batteries are insufficient to support this – particularly for greedy sensors like GPS and Bluetooth – we adopt a duty cycle strategy. After a certain preconfigured time, the phone will wake up and measure each of the channels for a set period of time. Much of designing an measurement protocol for an experiment is balancing the desire for more complete data with realistic battery life profiles. Custom schedulers can be implemented but require adaptation of iEpi code.


iEpi comes with the ability to issue on phone surveys, which can be triggered either contextually (for example through goefencing, when active, or proximate to a given individual), on a set schedule, based on a probability, or triggered by the participant. Random or detected events are typically tied to duty cycles. These surveys can be used to elicit perception, affect or context for the sensed activity and provide a powerful tool for understanding motivations underlying observed behaviours.

© Kevin Stanley 2014