This author states that a professional focus on evidence based practice (EBP) for school libraries emerged from the International Association of School Librarianship conference when he presented the concept. He challenged the school library profession to actively engage in professional and reflective practices that chart, measure, document, and make visible the impact of school libraries on learning outcomes. He argued that EBP for school libraries hinges on two concepts: (1) the conscientious, explicit and judicious use of current best evidence in making decisions about [school librarians'] performance. It is about using research evidence, coupled with professional expertise and reasoning, to implement learning interventions that are effective; and (2) [the school librarian's] daily efforts put some focus on effectiveness evaluation that gathers meaningful and systematic evidence on dimensions of teaching and learning that matter to the school and its support community (Todd 2001).