This page contains the findings of systematic reviews undertaken by review groups linked to the EPPI-Centre. This topic is included in the EPPI-Centre knowledge library. The Knowledge Pages facility enables users to search for the key messages within specific subject areas to which EPPI-Centre reviews have contributed.
This systematic review was commissioned by the Teacher Training Agency in order to contribute to such an evidence base. This systematic review was published by EPPI-Centre in 2004. Systematic reviews aim to find as much as possible of the research relevant to the particular research questions, and use explicit methods to identify what can reliably be said on the basis of these studies.