THOSE who would reform America's education system have focused tremendous energy on improving the nation's high in the last half-decade. And the high have proved less impervious to change than many believed they would be. Spurred by sobering reports of ill-prepared students and a billion dollars in funding from the Bill & Melinda Gates Foundation, policy makers nationwide have embraced the issue. Political, business, and education leaders convened at a National Education Summit on High Schools in Washington, D.C., in 2005. Later that year, the National Governors Association (NGA) awarded the first of nearly $24 million in grants to more than two dozen states to develop comprehensive high school improvement plans, and every governor has signed an unprecedented NGA pact to measure high school graduation rates more accurately. Commission reports, conferences, and research briefs have made a compelling case for reform. Only 68% of the nation's high school freshmen--and only about half of African American and Hispanic students--graduate on time. (1) Just 57% of high school graduates take the core academic courses proposed by a national commission two decades ago. (2) As a result, only one-third of high school freshmen graduate on time with the academic preparation necessary to succeed in college. (3) The Gates Foundation put high school reform on the national agenda when in 2000 it launched a five-year high school initiative. The Gates initiative focused on addressing the anonymity and resulting apathy and alienation that earlier reform proponents--among them Theodore Sizer in Horace's Compromise, his influential 1984 study of public high schools; Ernest Boyer in his 1983 report High School; and John Goodlad in his 1984 book A Place Called School--had identified as so detrimental to the productivity of public high schools. The Gates Foundation has captured the major underlying principles of today's high school reform movement--and the movement's ambitiousness--with a new version of the Three R's: rigor, relevance, and relationships. Reforms, Gates and others have argued, need to focus on raising academic standards, connecting students' studies to their lives outside of school, and addressing the anonymity of the nation's many large, comprehensive high schools. The high school reform movement resembles a sprawling 19th-century Russian novel, with dozens of actors and innumerable initiatives. But reformers are focusing primarily on five strategies--improving school climate, strengthening curriculum and instruction, raising graduation requirements, helping freshmen get up to speed academically, and preventing students from dropping out. At the same time, these reform efforts have been accompanied by an equally ambitious effort to gauge the effectiveness of the reforms. Researchers have conducted a range of studies on the high school reforms of the last half-decade. The results are just now starting to emerge, and they are more promising than many would expect. PERSONAL, CHALLENGING, ENGAGING Over the past seven years, the Gates Foundation alone has invested more than $1 billion to create more than 1,500 small learning communities of, optimally, fewer than 400 students each. Some were built from scratch while others were created by redesigning existing high and breaking them up into smaller, semi-autonomous units. The new (from-scratch) are replications of promising model schools that the foundation had identified throughout the country, such as High Tech High in San Diego. The foundation also invested $5 million in a major, multi-year evaluation of the initiative, conducted by two independent research organizations, the American Institutes for Research (AIR) and SRI International. Evaluators judged how well the were doing in the following areas: personally tailored learning, relationships based on mutual respect and responsibility, high expectations, a shared focus, and teacher collaboration. …