Samenvatting

In the Netherlands a system of evidence-based interventions was set up, in which only behavioural interventions which meet the scientifically proven ‘What Works’ criteria can be applied to well-defined categories of offenders. An accreditation commission was installed by the ministry of Security and Justice to test behavioural interventions. One of the crucial elements of this evidence-based policy is that the interventions are carried out according to protocol and are applied to the target group by well-trained personnel. This, however, is a problem in practice. Reasons for the low intervention integrity lie among others in lack of support and lead in the organisation and low inflow of participants. The integrity problems pose a risk to the effectiveness of behavioural interventions. Literature suggests that a 100% compliance to protocols might be necessary nor desirable. Causes that lie in the organisation could be improved and the implementation process could be given some more time. Evidence-based policy is not that easy to carry out in daily practice. The future will show whether the goal of a reduction of criminal recidivism will be realized.