This document contains a brief overview of the different ERs but is written primarily for those intending to commission and/or produce an ER in the form of Quick Scoping Reviews (QSR) or Rapid Evidence Assessments (REA), that lie between literature reviews and SRs in terms of rigour of assessment. These have been found to be well suited to meet the evidence challenges most frequently faced by the authors in meeting policy and practice evidence requirements. Whilst being less resource and time intensive compared to full SRs, QSRs and REAs are designed to be transparent and to minimise bias. QSRs and REAs can most readily be used to understand the impact either of a ‘pressure’ or a policy intervention. Additionally, a QSR can be applied to more open-ended questions such as ‘what do we know about x or y?’ Both forms of ER also provide an understanding of the volume and characteristics of evidence available on a certain topic and make it more accessible for further scrutiny if required. Hence, QSRs and REAs allow questions to be answered by maximising use of the existing evidence base, whilst also providing a clear picture of the adequacy of that evidence