This review has been undertaken on behalf of the Australian School Library Association (ASLA). It was conducted over a four-week period in November-December 2002. Because of the modest timeline the review is not exhaustive but focuses on the main studies carried out since 1990 on the relationship between school libraries and student achievement. Although a commonsense view would suggest the issue is a straightforward one-how could school libraries not contribute to student learning, for example-this is not necessarily the case. Not only is there a range of variables that need to be taken into account in determining the nature of the impact of school libraries on student achievement but also the concept of 'student achievement' itself is not used consistently by studies. Most commonly it has been measured in terms of student performance on standardised tests, although some studies have equated it with literacy development or student learning more generally. Increasingly, there is interest in trying to measure the contribution that school librarians make in regard to students' information literacy skills.
The role, responsibilities and qualifications of library staff are also not necessarily the same in all studies. Reynolds and Carroll (2001), for example, note a range of terms employed to describe library staff, including library teacher, library manager, information technician, resource centre manager, specialist library information teacher, library co-ordinator and resource co-ordinator. Their survey of 197 Victorian primary schools reveals that some individuals who called themselves librarians did not always have any library qualifications and that some who called themselves teacher librarians did not always have a teaching qualification. These findings led the researchers to question the implications of the various terms and whether the title used affects our perceptions of the role. In the United States the Australian 'teacher librarian' becomes a 'library media specialist', and in England and Scotland, where the role traditionally does not include teacher training, a 'librarian'. Reynolds and Carroll (2001) define a teacher librarian as 'a specialist teacher in a specialist classroom who, to perform the role, must have specialist teacher librarianship training'. In this review of the literature the terms school library and school librarian or library professional have been used to avoid confusion and to indicate a member of the school library staff with specialist teacher training.