The reading and mathematics measures of the National Assessment of Educational Progress (NAEP) have been, and continue to be, reported on scales that appear to have the properties of “cross-grade” scales: Reported scores are higher for 8th-grade students than for 4th-grade students, and higher for 12th-grade students than for 8th-grade students. Historically, these scales were developed in ways that were intended to support cross-grade interpretation; however, the degree of support for and endorsement of such interpretations has varied over the past two decades. Nevertheless, these score scales invite interpretive statements about the results. The conclusion of this essay will be that evidence can and should be assembled to support, and make more precise, certain interpretations, while others interpretations should be discouraged.