Almost every state has in place a state assessment and accountability system. These systems vary greatly in their characteristics but share a common global purpose of improving teaching and learning. Some of the variations in the state systems are discussed and illustrated with examples from selected states. Issues that are critical to the value and interpretation of results such as the use, if any, of comparisons among schools that serve students who come from different socioeconomic backgrounds, the relative weight given to current status or to improvement, and the basis for judging improvements at the school level (i.e., cross-sectional comparisons, quasi-longitudinal, and true longitudinal designs) are compared. The importance of evaluating and reporting the precision of assessment and accountability results is discussed. Finally, a key validity issue--the degree to which reports of performance and improvement based on observed assessment results support inferences about student learning-- is addressed. Evaluations of the degree of generalizability of results and trends through comparisons to other indicators of achievement and of improvement such as the National Assessment of Educational Progress are stressed. (Contains 3 tables, 1 figure, and 38 references.) (Author/SLD)