“…Although there are many possible explanations for the implementation gap that appears to exist between correctional policy and rehabilitative practice, one that is commonly proposed identifies the environmental and interpersonal context in which rehabilitation programs are offered as placing significant constraints on program delivery (Shefer, 2010). This is an important issue for policy makers and practitioners alike, given the relatively recent development of specialist therapeutic prisons whose primary aim is to rehabilitate (e.g., prison drug units in the United States; Wexler, 1995; the Dangerous and Serious Personality Disordered services in the United Kingdom; Howells & Tennant, 2007). In addition, there is a history of specialist units being set up within correctional facilities to manage particular offender groups, such as serious violent offenders (Cooke, 1992; Day & Doyle, 2010).…”