David T. Gordon is editor of the Harvard Education Letter, the award-winning publication on K-12 education, and of the book *The Digital Classroom: How Technology is Changing the Way We Teach and Learn*.

Timothy Knowles is the Lewis-Sebring Director of the Urban Education Institute. The mission of the Urban Education Institute is to create new knowledge and educational models to address one of the nation's most significant and enduring questions: how do we produce reliably excellent schooling for children growing up in urban America? Prior to his current position, Knowles served as the Lewis-Sebring Executive Director and Senior Research Associate of the Center for Urban School Improvement at the University. He was deputy superintendent for teaching and learning at the Boston Public Schools from 1998 to 2002. At the Boston Public Schools, he has been responsible for school improvement and professional development, developing and sustaining community partnerships, and supervising principals and district staff. He was co-director of the Boston Annenberg Challenge, a $30 million effort to improve literacy instruction, and has served in a number of other administrative positions, including founding director of a full-service, kindergarten-through-eighth-grade school in Bedford-Stuyvesant, New York City.

Kim Marshall began his career in 1969 teaching sixth graders in a Boston middle school. He used "learning stations" with some success, wrote curriculum materials for his students, gave workshops for teachers in the Boston area, and began to write articles on classroom and school innovation. In 1987, Kim was made a principal. As leader of the Mather Elementary School for the next 15 years, Kim and his colleagues brought about significant improvements in student achievement, teacher effectiveness, and the quality of the curriculum. Kim now works for New Leaders for New Schools, a non-profit that recruits, trains, and supports urban principals. Kim coaches new principals in New York City, with a special focus on the effective implementation of interim assessments

Jeff Howard is founder and president of The Efficacy Institute, a national, not for profit agency of education reform. The Efficacy Institute is committed to the mission of developing all young people to high standards, particularly children of color and the economically disadvantaged. Howard holds an AB from Harvard College and a PhD in Social Psychology from Harvard University.

Gerald Holton is Mallinckrodt Professor of Physics and Professor of the History of Science, Emeritus at Harvard University. Holton obtained his PhD at Harvard as a student of PW Bridgman. His chief interests are in the history and philosophy of science, in the physics of matter at high pressure, and in the study of career paths of young scientists.