Background/Context: There is a deep and yawning chasm between the world of tests and testing practices as they ought to be and the actual tests and testing practices now imposed on American students, educators, and schools. That chasm of theory and practice is a function of the dominant paradigm of educational reform, with its theory of action that schools must be remade in the image and likeness of a corporation. Purpose: To explore the role, development, and implications of assessment use in the market model of education reform. Research Design: Analysis of the recent publication of the value-added measurements found in the Teacher Data Reports of the New York City Department of Education. Conclusions: Since standardized tests provide data for a "bottom line," they have been widely embraced in some circles as a basis for making "high stakes" decisions that hold individuals and schools accountable. In the market model of education reform, questions about the validity and reliability of the tests and of their use for "high stakes" decisions are dismissed as efforts to avoid accountability.