"A systematic review attempts to identify, appraise and synthesize all the empirical evidence that meets pre-specified eligibility criteria to answer a given research question. Researchers conducting systematic reviews use explicit methods aimed at minimizing bias, in order to produce more reliable findings that can be used to inform decision making." Source: Cochrane Handbook for Systematic Reviews of Interventions
Key characteristics of a systematic review are:
Margaret Bearman , Calvin D. Smith , Angela Carbone , Susan Slade , Chi Baik , Marnie Hughes-Warrington & David L. Neumann (2012) Systematic review methodology in higher education. Higher Education Research & Development 31(5), 625-640. doi: 10.1080/07294360.2012.702735