Choosing alternative covariate summaries for reweighting

Determine how to choose a summary of the covariates, other than the prediction function, through which reweighting should be performed for a given family of distribution shifts.

Background

The reweighting construction can preserve conditional response distributions when the weights depend on a covariate summary, not only when they depend on the prediction. This broader formulation could target families of shifts represented through other summaries, but the paper does not specify how an appropriate summary should be selected for a particular shift family.