Conceptual framework The assumptions, theories, values or logic model underlying the review question are made explicit in order to inform the approach to answering that review question.

Data extraction So that each study in a systematic review can be scrutinised, and its quality and relevance systematically appraised, details of the methods and results are captured using a set of usually pre-determined questions and answers.

Empirical Derived from observation and/or experiment (as opposed to ‘conceptual’ or ‘theoretical’).

Evidence Research evidence is knowledge and understanding developed by empirical and conceptual research. There are many types of research, all with their own methodology for creating and evaluating evidence.

Evidence informed policy and practice The use of sound research evidence in an explicit and systematic way to inform decisions, policy making or for practice.

Keywording In order to be able to describe the available literature on a given topic in a ‘systematic map’, brief information on a limited number of characteristics of studies is coded. This coding is called ‘keywording’ just as you have keywords to describe studies in journals and on bibliographic databases.

Meta-analysis The statistical data from a group of studies is pooled and re-analysed as one large data set. This enables conclusions to be drawn when each individual data set is too small to provide reliable evidence.

Narrative Using words/text to describe facts or events or theories and concepts, to establish connections and construct arguments.

Screening Comparing individual studies against explicit criteria to assess whether they are relevant for answering a review’s question.

Search strategy An explicit strategy is used to locate relevant studies via a number of different resources such as electronic databases, relevant journals, specialist websites and specialists in the field.

Synthesis The part of the systematic review process in which the findings of multiple studies are combined.  It involves a transformation of the primary data in order to arrive at an overall conclusion which is more than just a summary of its parts.  The synthesis combines evidence to see what can reliably be said on the basis of existing, relevant studies in answering the review question.

Systematic map Part of the review process that systematically identifies and describes the research that has been undertaken within the boundaries of the review question.

Systematic review A review of research that aims to be principled, methodical and explicit. A systematic review addresses a clearly defined research question and uses explicit and standardised methods to identify and review the literature.

User Anybody who uses research, including, for example, policy makers, practitioners, users of services and researchers.

Weight of Evidence The EPPI Centre’s framework for appraising individual studies. A conclusion about overall study ‘weight’ is reached by considering its methodological soundness; the appropriateness of the study design to answering the review question; and relevance of the focus of the study.