Abstract
This paper argues that educational policy and practice has much to gain from systematic reviews and other methods of research synthesis. Different types of reviews are considered, including narrative reviews, vote-counting reviews, meta-analyses, best evidence synthesis, and meta-ethnography. It is argued that systematic reviews allow researchers, and users of research, to go beyond the limitations of single studies and to discover the consistencies and variability in seemingly similar studies. This, in turn, allows for some degree of cumulative knowledge of educational research that is often missing in the absence of systematic reviews. Some limitations of systematic reviews and research synthesis for educational policy and practice are also discussed. The work of the Campbell Collaboration as an international organisation that promotes the use of systematic reviews in educational policy and practice is outlined.