The aim of the research was to develop a framework for measuring the outcomes of mentoring or arts interventions for offenders. The focus was on ‘intermediate outcomes’, defined here as measurable changes in individuals that are directly or indirectly associated with reductions in reoffending. Such outcomes may also produce other social and individual benefits, independent of any demonstrable effect on offending.

The main objective was to design and develop a robust but user-friendly instrument to measure changes of the above kind. A theoretically informed 29-item questionnaire, named the Intermediate Outcomes Measurement Instrument (IOMI), was produced through an iterative process of literature searches, consultation, piloting and analysis. IOMI has not undergone full validity and reliability testing, but the results of initial testing have been encouraging.

The IOMI forms part of a broader toolkit for service providers to assist them in evaluating their work. The toolkit includes: guidance on the administration of IOMI and how it could be used as part of wider evaluations; a data entry tool to facilitate the collection and analysis of IOMI data; and a tool for the collection and presentation of cost data.

While the IOMI was developed for use in arts or mentoring interventions with adult male offenders, it is likely that it will have wider applicability to other intervention or groups. Its main purpose is to provide evidence of offenders’ progress towards desistance, which is not necessarily reflected in standard reoffending rates. This could be particularly valuable for capturing any contribution to desistance made by individual interventions which are not expected to reduce reoffending on their own.