Question to the Ministry of Justice:

To ask the Secretary of State for Justice, whether he has made an assessment of the usefulness of assessments made under the Offender Assessment System in probation.

OASys is the core risk assessment tool utilised by Her Majesty’s Prison and Probation Service to assess the risks and needs of any offender. The system was built based on existing evidence and was piloted prior to its implementation in 2001.

There have been a number of research reports since its implementation, and there is a current validation exercise of the predictive element of it, all of which have helped to ensure it remains a valid and reliable tool for assessing offenders’ risk.

The first research report, which covered a period between 2006 and 2009, outlined that OASys had contributed to the reduction of reoffending and can be found here: A compendium of research and analysis on the Offender Assessment System (OASys) 2006-2009 (cep-probation.org).

A second report presents the OASys studies completed between 2009 and 2013, including a systematic review of the usefulness of the tool and analyses of various aspects of reliability and validity: A compendium of research and analysis on the Offender Assessment System (OASys), 2009–2013 (publishing.service.gov.uk).

The OASys Sexual reoffending Predictor was introduced after the compendiums were written, and the evaluation of that tool is also available:

https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/955345/comparing-2-predictors-sexual-recidivism.pdf.