Among the five roles--leader, instructional partner, information specialist, teacher, and, program administrator--identified for the school librarian in "Empowering Learners: Guidelines for School Library Media Programs" (AASL, 2009), the role of teacher is critical for improving student achievement. The school librarian is uniquely positioned in the education matrix to gain greater professional credibility by participation in decision-making discussions about reporting standardized test data and designing data-driven instruction, thus communicating student achievement as measured by standardized test results. The areas of focus of this article are to: (1) present general information associated with interpreting and sharing test data; and (2) identify strategies and resources the school librarian may utilize in expanding professional competence in using test data. (Contains 2 figures.)