The recent federal push under the No Child Left Behind Act to finalize means for gauging school improvement has stoked public anxiety, especially for public school officials who are charged with crafting and implementing defensible accountability systems. Other than the omnipresent political issues attending any proposal for shaping educational change, the methodological challenges of an accountability system are indeed daunting. Although this paper does not make it explicit in terms of specific references, the paper sketches a conceptual analysis and outlines recommendations for a viable accountability system that is based on recent research. Readers familiar with the issues will find a number of not-so-familiar answers to many of their concerns, including: (1) what is value-added "productivity"; (2) what data structure is sensible; (3) what might the minimum school size be in order to attain the minimum level of precision; (4) how to define and estimate "adequate yearly progress"; and (5) how to evaluate compliance under the so-called "safe-harbor" provisions. (Author/SLD)