Three key terms--social studies, values, and attitudes--are discussed in relation to a national assessment in social studies. Definitions of these terms will affect decisions about what and how to assess. Two major approaches define social studies as: (1) social sciences simplified and adapted for pedagogical purposes; or (2) that portion of the school curriculum which is focused specifically on citizenship education. Curricular and assessment implications of choosing a definition become clearer when the objects of assessment--values and attitudes--are defined and linked to a definition of social studies. The citizenship education role of social studies should not only be acknowledged, but taken as the centering concept in a national assessment. Acceptance of that perspective, along with the careful definition of values and attitudes, suggests significant and feasible areas of assessment. Careful analysis of prior National Assessment of Education Progress (NAEP) work and the consideration of measurement alternatives can produce results which are more meaningful, useful, and valid than those from prior NAEP social studies assessments. (LMO)