Background: Much is still unknown or unclear about how and where validity issues arise in high stakes testing situations in education, and ways by which we can rectify validity problems in practice and policy contexts. Purpose: This paper is the Foreword to the Special Section in the "Teachers College Record," titled, "When Education Measures Go Public--Stakeholder Perspectives on How and Why Validity Breaks Down." Method: The paper analyzes a recent case involving an application of the SAT® to highlight tensions between validity and test score use in high stakes school accountability environments driven by the No Child Left Behind (NCLB) Act of 2001. It uses the case study as a vehicle to introduce the individual papers and authors in the section. Conclusions: There are information and power gaps among those who set societal priorities for using tests for high stakes purposes, those who design and conduct psychometric research on tests and testing programs, and those who could eventually face consequences of assessment misuse. These gaps could be addressed through thoughtful exchanges among key assessment stakeholders, as this special issue shows.