Stage 3: Coding the studies

​Crime clearly takes many forms; so too do methods intended to reduce it. Consequently, of the systematic reviews identified in stage 1, some focus on particular interventions (e.g. the impact of CCTV on crime, or the impact on offending of electronic monitoring), whilst others consider a series of interventions that may address a general problem (e.g. juvenile offending). The decision was made to concentrate on systematic reviews of the former kind initially since their singular focus provides more unequivocal evidence regarding a particular intervention. However, where further relevant evidence on the intervention in question was available in reviews of the latter kind, this was included in the material generated for the toolkit. In some cases, multiple reviews exist on the same intervention. Our process used the review of the highest quality as the basis for the evidence.

Where two or more reviews were of the same quality, we used the most recent. Where other reviews produced further reliable evidence, this was integrated. Where they provided no new reliable findings or were subsumed by others they were not included.
Two independent reviewers coded each review using the EMMIE framework. Coders compare their ratings and moderate their scores to agree a final set. Each dimension of EMMIE comprises a number of sub elements (see, Johnson et al., 2015), so a coding spreadsheet – which includes over 100 items – was developed to systematically capture each coder's ratings (Tompson et al, 2015). To ensure the final quality rating generated from these 100 items was consistently rated across reviews, the spreadsheet has scoring rules (embedded as excel formulae) and automatically produces an EMMIE-Q profile for each review.

Go to Stage Four of Method Statement