Offering a counter-narrative to the school improvement prescriptions that dominate national education debates, a new book based on 15 years of data on public elementary schools in Chicago identifies five tried-and-true ingredients that work, in combination with one another, to spur success in urban schools. The authors liken their "essential supports" to a recipe for baking a cake: Without the right ingredients, the whole enterprise just falls flat. The book is a capstone effort for the Consortium on Chicago School Research, which was founded 20 years ago at the University of Chicago by Anthony S. Bryk and others to undertake independent research on that city's 409,000-student school system. Besides Mr. Bryk, who left the consortium in 2003 to lead the Carnegie Foundation for the Advancement of Teaching, in Stanford, California, the book's authors are Penny Bender Sebring and Elaine Allensworth, the consortium's interim co-executive directors; Stuart Luppescu, its chief psychometrician; and John Q. Easton, the consortium's former director and now the director of the Institute of Education Sciences at the U.S. Department of Education. Based on a series of studies drawn from the database that the consortium has built up over the years, the five ingredients are: (1) Strong leadership, in the sense that principals are "strategic, focused on instruction, and inclusive of others in their work"; (2) A welcoming attitude toward parents, and formation of connections with the community; (3) Development of professional capacity, which refers to the quality of the teaching staff, teachers' belief that schools can change, and participation in good professional development and collaborative work; (4) A learning climate that is safe, welcoming, stimulating, and nurturing to all students; and (5) Strong instructional guidance and materials.