nbauman writes "According to Gina Kolata in the New York Times, The Institute of Education Sciences in the Department of Education Sciences, U.S. Department of Education, has supported 175 randomized controlled studies, like the studies used in medicine, to find out what works and doesn't work, which are reported in the What Works Clearinghouse. Surprisingly, the choice of instructional materials — textbooks, curriculum guides, homework, quizzes — can affect achievement as much as teachers; poor materials have as much effect as a bad teacher, and good materials can offset a bad teacher's deficiencies. One popular math textbook was superior to 3 competitors. A popular computer-assisted math program had no benefit. Most educators, including principals and superintendents, don't know the data exists. 42% of school districts had never heard of the clearinghouse. Up to 90% of programs that seemed promising in small studies had no effect or made achievement scores worse. For example a program to increase 7th-grade math teachers' understanding of math increased their understanding but had no effect on student achievement. Upward Bound had no effect."