By mid 2001, researchers affiliated with the Library Research Service of the Colorado State Library and the University of Denver had completed four statewide studies on the impact of school library media programs on the achievement of U.S. public school students: Information Empowered: The School Librarian as an Agent of Academic Achievement in Alaska; Measuring UP to Standards: The Impact of School Library Programs and Information Literacy in Pennsylvania Schools; How School Librarians Help Kids Achieve Standards, The Second Colorado Study; and Good Schools Have School Librarians: Oregon School Librarians Collaborate To Improve Academic Achievement. Among the four states, different grades were tested at different levels but, generally, each state tested at elementary, middle, and high school levels. In each state, school library media programs were surveyed at the building level on a variety of topics. The topics common to all four state studies were: staffing levels, staff activities, collection size, usage statistics, and available technology. While the results of the four studies varied somewhat, on the whole the findings concerning what aspects of school library media programs are important were remarkably consistent. Findings for each of the states are highlighted, followed by common findings and distinguishing results of each study. The remainder of the digest discusses controlling for school and community differences, implications and recommended actions by school officials, and other research questions raised by these studies. (AEF)