This report describes the derivation and evaluation of a method for comparing the performance standards for public school students set by different states. It is based on an approach proposed by McLaughlin and associates, which constituted an innovative attempt to resolve the confusion and concern that occurs when very different proportions of students in various states are declared to have met a standard with the same label. Our method, like McLaughlin's, employs equipercentile methods to map state standards on to a common scale, that associated with the National Assessment of Educational Progress (NAEP). We have also derived error estimates that take into account both NAEP's complex sampling design and measurement errors. The method was applied to two data sets, and the results were qualitatively similar to those obtained by McLaughlin's method. The paper notes the superior statistical properties of the proposed method and presents evidence that supports the viability and general utility of this approach.