The North Carolina End-of-Grade (NCEOG) Test of Mathematics, Grade 8 was compared to the National Assessment of Educational Progress (NAEP)--Grade 8 along three dimensions: technical, content, and cognitive. An expert panel of six judges (mathematics educators) examined the supporting documents, the content frameworks, the items, and actual test forms to determine the level of congruence between the two assessments. Although differences were observed between the two assessments on each of the three dimensions, they were not enough to explain the differences in student performance on the assessments. The most important result of the study was a clearer understanding of the NCEOG, and following that an improved understanding of the NAEP. Further research to investigate the differences between the two assessments is outlined. (Contains 4 tables and 14 references.) (SLD)