Source: (2001) In Community penalties: Change and challenges, eds. Anthony Bottoms, Loraine Gelsthorpe, and Sue Rex, 117-125. Cambridge Criminal Justice Series. Devon, UK: Willan Publishing.In this chapter Underdown comments on opportunities and challenges with respect to the 'what works' initiatives for probation services in the United Kingdom in the late 1990s. Underdown maintains that a central challenge to such rehabilitative programs lies in compliance and engagement; that is, the issue of an offender's success in satisfying probation requirements and thus completing community-based rehabilitation programs. In view of this, he discusses strategies for probation services to improve prospects for offender compliance and success in rehabilitation.