Combining Evidence Across Independent Strata

Abstract

A frequently occurring situation is this: a party seeking to show statistical significance combines data from different sources to create larger numbers and hence greater significance for a given disparity. Conversely, a party seeking to avoid finding significance disaggregates data insofar as possible. In a discrimination suit brought by female faculty members of a medical school, the plaintiffs aggregated faculty data over several years, while the school based its statistics on separate departments and separate years (combined, however, as discussed below).