Title: Statistical and Ethical Considerations in the Analysis of Mobile Phone Tracking Data
Abstract:
In the biomedical and social sciences, mobile phone tracking (MPT) data — collected using location sensing-technologies readily available on smartphones — has become an increasingly common component of cohort studies, where it has been employed for purposes of digital phenotyping or estimating personal exposure to the ambient environment or particular social contexts. In this talk, I will provide an overview of some of the statistical challenges that arise when working with MPT data for research purposes. I will then provide an in depth investigation into the consequences of MPT study design choices from a formal missing data perspective. To do so, I will introduce a novel statistical model that formalizes the so-called flight-pause paradigm for human movement as a likelihood for a random object, called a motion, made up of increments of changes in space and time. Under this model, it is possible to perform both inference on unknown model parameters and trajectory imputation under various forms of missing data that are ubiquitous in practice. Under this model, it is possible to illuminate the consequences of different MPT data collection mechanisms, including the surprising result that common assumptions about the missing data mechanism for MPT are not valid for the mechanism governing the random motions of the flight-pause model. The consequences of missing data and proposed adjustments will be illustrated using both simulations and real data, showing how the statistical formulation we propose can serve as a foundation for continued statistical research on MPT data collection, design, and analysis. Finally, I will briefly discuss some ethical considerations related to the use of MPT data for research purposes. Part of research presented is based on joint work with Marcin Jurek and Cory Zigler.
