“…The little research that exists on responsivity has mostly focused on the programme or process factors that enhance treatment outcomes (Marshall, Marshall, & Burton, 2013), such as the use of social learning principles, the importance of therapeutic alliance (Kozar & Day, 2012;Watson, Daffern, & Thomas, 2015), and effective strategies for programme delivery (Marshall & Marshall, 2012). Limited research has focused on whether, and how individual offender characteristics influence the effectiveness of violence intervention programmes (Scott & King, 2007). Although numerous internal offender characteristics have been highlighted as possible barriers to treatment participation (e.g.…”