Before revision:  We frame this challenge as a pattern detection problem where we  maximize a nonparametric scan statistic (measurement of distributional divergence) over subpopulations, while being parsimonious in which specific subpopulations to evaluate .
After revision:  We frame this challenge as a pattern detection problem where we efficiently maximize a nonparametric scan statistic (measurement of distributional divergence) over subpopulations, while being parsimonious in which specific subpopulations to evaluate .