For almost two decades now, educational accountability policy in the U.S. has included a focus on the performance of student subgroups, such as those defined by race and ethnicity, income, or special education status. The (very sensible) logic behind this focus is the simple fact that aggregate performance measures, whether at the state-, district-, or school levels, often mask large gaps between subgroups.
Yet one of the unintended consequences of this subgroup focus has been confusion among both policymakers and the public as to how to interpret and use subgroup indicators in formal school accountability systems, particularly when those indicators are expressed as simple “achievement gaps” or “gap closing” measures. This is not only because achievement gaps can narrow for undesirable reasons and widen for desirable reasons, but also because many gaps exist prior to entry into the school (or district). If, for instance, a large Hispanic/White achievement gap for a given cohort exists at the start of kindergarten, it is misleading and potentially damaging to hold a school accountable for the persistence of that gap in later grades – particularly in cases where public policy has failed to provide the extra resources and supports that might help lower-performing students make accelerated achievement gains every year. In addition, the coarseness of current educational variables, particularly those usually used as income proxies, limits the detail and utility of some subgroup measures.
A helpful and timely little analysis by David Figlio and Krzystof Karbownik, published by the Brookings Institution, addresses some of these issues, and the findings have clear policy implications.