Each study is mapped into the Matrix by a different color-coded circle. These color codes indicate whether an intervention was successful, had mixed results, did not show any effects, or was harmful:
Successful Intervention– The study found statistically significant findings that indicated this intervention was successful in reducing crime, criminality, or fear of crime.
Example: A randomized controlled experiment showed that when police target specific hot spots of crime, they can significantly reduce crime
at those places.
A Harmful Intervention or “Backfire” – The study found statistically significant findings that indicated this intervention was harmful, leading to an increase in crime, criminality or fear.
Example: Mandatory arrest for domestic violence was shown to significantly increase recidivism among unemployed suspects.
Mixed Results– There were multiple primary outcomes in the study, at least one of which showed positive effects, and at least one whichshowed no significant effect or a backfire effect of the intervention on crime, criminality or fear, or outcomes were only positive for a certain subgroup of targeted offenders/places. We recognized that most studies may have both significant and nonsignificant findings and coded a study as having mixed results only when the authors emphasized the mixed nature of the findings (see examples below).
Examples: Restorative justice reduces recidivism for violent crime but not property crime (see Sherman et al., 2000)
Crack house raids reduced crime but only for a 12 day period (see Sherman & Rogan, 1995)
Non-Significant Finding – No significant finding was discovered that would indicate the intervention creates an impact on crime, criminality or fear.
Example: A gun buy-back program showed no effect on the reduction of gun crimes in a city.