Chapter 1 Introduction to OASys classification, targeting needs and responsivity are less effective at reducing reconviction (Andrews et al , 1990). An effective risk needs assessment It is clear that in order to adhere to these principles, effective and systematic methods of risk and needs assessment are essential. Indeed the proliferation of needs assessment tools within criminal justice agencies has, to some extent, been prompted by this requirement. An effective risk/needs assessment must perform many functions. It must provide a broad classification of likelihood of reconviction within a given time frame.
It must separately identify the serious risk of harm should further offences occur and to whom the risk of harm is posed and in what circumstances. It must provide an offending related needs profile, and direct steps to reduce these needs. It must identify responsivity issues, such as ability and motivation to change, and any other factors that could affect the individual’s response to a specific intervention. What is OASys? OASys is a new national system for assessing the risk and needs of an offender. The decision was taken to develop a new risk assessment system because none of the existing tools and inventories fully met the requirements specified by the project team.
The Prison and Probation Services have jointly designed the system. OASys is designed to: ! assess how likely an offender is to be reconvicted ! identify and classify offending-related needs, including basic personality characteristics and cognitive behavioural problems ! assess risk of serious harm, risks to the individual and other risks ! assist with management of risk of harm ! link the assessment to the supervision or sentence plan ! indicate the need for further specialist assessments ! measure change during the period of supervision/sentence. Benefits of OASys OASys is a central part of evidence-based practice.
It is designed to be an integral part of the work which practitioners do in assessing offenders; identifying the risks they pose, deciding how to minimise those risks and how to tackle offending behaviour effectively. OASys is designed to help practitioners to make sound and defensible decisions. OASys Manual V2 © Crown Copyright 2002 Page 3