Qatar has recently positioned itself to be a leader in education. Central to the country's efforts is the implementation of reforms to its K-12 education system. Central to the reform initiatives was the development of internationally benchmarked curriculum standards in four subjects: Arabic, English as a foreign language, mathematics, and science. To develop a method of testing student achievement in relation to the curriculum standards, a RAND study team worked with Qatar's Evaluation Institute between 2002 and 2006 to create the Qatar Student Assessment System (QSAS). The core component of the QSAS is the Qatar Comprehensive Educational Assessment (QCEA), a summative assessment administered to students in grades 4-11 in newly developed Independent schools. This report recounts the development of the QSAS and the QCEA, the changes made to the testing operation as the reform initiative progressed, the data and knowledge gleaned from QCEA administrations, and important lessons learned for Qatar and other countries that are seeking to implement similar standards-based assessment systems on a large scale. Three appendixes are included: (1) Assessment Elements Considered for the QSAS; (2) Steps to Align Assessments with Curriculum Standards; and (3) Performance-Level Results of 2005 and 2006 QCEAs for Ministry of Education, Private Arabic, and Independent Schools. A list of abbreviations and a glossary are also provided. (Contains 34 footnotes, 3 figures, and 12 tables.) [This report was prepared for the Supreme Education Council.]