The Impact of School Library Media Centers on Academic Achievement.

Students whose library media specialists played [an instructional] role—either by identifying materials to be used with teacher-planned instructional units or by collaborating with teachers in planning instructional units—tend to achieve higher average test scores.—Lance, Keith Curry, Lynda Welborn, and Christine Hamilton-Pennell. The Impact of School Library Media Centers on Academic Achievement. Colorado Department of Education, State Library and Adult Education Office. Prepared for the U.S. Department of Education, Office of Educational Research & Improvement Library Programs. September 1992. p. 97.

The full text, 152 page, pdf is available at this link: http://eric.ed.gov/PDFS/ED353989.pdf