Chapter 2 The development of OASys OASys 1 and OASys 2 There are two versions of OASys Sections 1 – 13: OASys 1 and OASys 2. OASys 2 has a longer offence analysis section, and contains more items in Sections 1 – 12. It contains more dynamic items, which means that it is more sensitive to change and monitoring progress . All the OASys 1 questions are contained in OASys 2 so that an initial OASys 1 assessment can be expanded into the fuller version. Three sets of paper forms are available: OASys 1, OASys 2 and a combined form. The combined form contains the OASys 1 questions within OASys 2, and allows for ease of updating from OASys 1 to OASys 2.
The Probation OASys Management Manual and supporting Prison Service operational guidance will provide advice about which version to use when, and other operational issues. Research background to Sections 1 – 12 Here we provide a brief description of each section and the research linking it to reconviction . You can find more detailed information about Sections 1 – 12 and Section 13 in Chapter 6. Section 1: Offending information Past behaviour is invariably the best predictor of future behaviour.
This is true of criminal behaviour, where every research study in this country and abroad has demonstrated that criminal history is a very good predictor of future reconviction (Nuttall, 1996; Cornish & Clarke, 1975; Andrews, 1983; Copas et al , 1994; May, 1999). Indeed it would be difficult to do a proper analysis of likelihood of reconviction without criminal history. Many of the items in this section are comparable with the variables used by OGRS 2 and the Sentence Planning Risk Predictor score. This section is given the greatest weighting in prediction of re-offending Section 2: Analysis of offences Different offences have different reconviction rates.
For example, offenders who are convicted of burglary are likely to be re-convicted more quickly than those who commit a sexual offence (Taylor, 1999). This is taken into account by the OGRS 2 scores. The pattern of re-offending has also been linked with early offending. Other aspects of the offence such as the number and type of victims, the number of occasions on which the offence occurred, the use of weapons, the location, and motivation are vital in identifying the risk of serious harm, risks to the individual and other risks.
Much of the current offence analysis section is related to identifying features that suggest risk of harm, rather than scored in terms of the likelihood of reconviction. You can find discussion on the value of offence analysis material in predicting reconviction in Lee-Evans (1994). OASys Manual V2 © Crown Copyright 2002 Page 14