Why What Works Works

Objective: The aim of this thesis was to contribute to the evidence base on understanding who benefits from rehabilitative interventions with offenders. Tens of thousands of offenders have attended offending behaviour programmes in the UK over recent years and while the international literature confirms their value in reducing reoffending demonstrating their worth has been more problematic in this country and we know little about who benefits most, or not at all, from this approach. Method: The four studies in this thesis applied observational and quasi-experimental research designs. The intention was to observe the impact of the cognitive skills programmes, ETS and TSP, in their routine delivery – using as a counterfactual, first, the reconviction rate of a large cohort of similar offenders; second, the offender’s own predicted reconviction rate and third, a comparison group with control for propensity for selection onto the programme and for other risk, need and responsivity characteristics. The main analytical tests applied were Chi-square tests and logistic regression as the outcome in every study was the binary reconviction rate. Results: In each study a significant and positive impact of programme attendance was found – that is for both men and women, on ETS and TSP, in prison and the community. In terms of who most benefitted the findings in this thesis suggest that index offence type is associated with different post-programme outcomes although this is less apparent with the current programme in the community setting. Less equivocal is the finding that offenders who do not meet the programme’s suitability criteria on risk level and relevant needs do not benefit, and may even fare worse than those who did not attend. Significant problems were observed in the community implementation around appropriate targeting and attrition rates. Conclusion: One of the unique aspects of this thesis has been the opportunity to exploit the administrative data on routine delivery in order to provide a picture of programme impact in large-scale, real world practice. These were not so much samples of participants as whole populations of offenders attending the programme over an extended period. The most consistent observation across the studies was the lack of impact when offenders were wrongly targeted; those who benefit most are those for whom the programme was designed. The real-world relevance of these findings is profound: we must focus limited resources where they will make a difference.