Systematic and Nonsystematic Reviews: Choosing an Approach

Abstract

Systematic reviews and purposive (nonsystematic) reviews serve valuable and complementary roles in synthesizing the results of original research studies. Systematic reviews use rigorous methods of article selection and data extraction to shed focused, deep light on a relatively narrow body of research, yet of necessity may exclude potentially insightful works that fall outside the predefined scope. Purposive reviews offer flexibility to address more far-reaching questions and pursue novel insights, yet offer little assurance of a balanced perspective on the issue. This chapter reviews the strengths and weaknesses of each approach, and suggests specific questions to help researchers select among these approaches. Different approaches to quantitative and narrative research synthesis, including meta-analysis, are also described.