ABSTRACT

The essential ingredient of a systematic review of existing research on a particular topic is that it should be carried out with the aim of reducing as much as possible the potential bias inherent in other types of reviews; those often referred to as ‘narrative’ reviews of the literature. Examples of these narrative reviews can be found in the opening section of the vast majority of journal articles. The total elimination of bias is almost certainly impossible but a systematic review attempts to reduce bias by ensuring that it is carried out by a team of reviewers, that it is transparent in its procedures from beginning to end of the process and that the searching for relevant studies is not only exhaustive but reliable. A systematic review of relevant research aims to produce syntheses containing clear messages about the reliability of the evidence reviewed and these messages should be of benefit to practitioners. This chapter will enumerate the various challenges of carrying out a systematic review in the field of applied linguistics – challenges which are all the more noticeable when one considers the enormous breadth of the field making what to include and what to exclude one of the major considerations of the process.