Ever since the 2001 passage of the No Child Left Behind Act (NCLB), states have faced a federal mandate to improve their ability to collect and analyze education data for the purpose of tracking and reporting the progress of their education reform efforts. With the assistance of federal funds, virtually all of the states are developing comprehensive state data systems that track students' academic progress longitudinally throughout their primary, secondary, and even post-secondary careers. The Data Quality Campaign, an independent national organization, has played a complementary role in supporting states' efforts to improve their student data systems. Beyond student assessment, the comprehensive data systems developed by most states also enable them to correlate the academic gains of their K-12 students with their assignment to particular teachers and thus to assess the effectiveness of individual teachers as well. The analysis gap threatens to compromise the success of a wide range of current education reform efforts. This document discusses the gap and what the government is doing to attempt improve to collect and analyze data. The following topics are covered in this report: (1) The Growing State Data Capacity; (2) States' Data Analysis Gap; (3) Compromising Reforms; and (4) Expanding States' Research Capacity.