Supervision is probably the single most effective method for helping therapists to develop competence, capability and a professional identity (Falender & Shafranske, Reference Falender and Shafranske2004; Callahan et al. Reference Callahan, Almstrom, Swift, Borja and Heath2009; Watkins & Milne, Reference Watkins and Milne2014). Supervision is also perceived by supervisees as the main influence on their practice (Lucock et al. Reference Lucock, Hall and Noble2006), and has been recognized by governments as an essential component of mental health services in the 21st century (e.g. Care Quality Commission, 2013). Paradoxically, supervisors themselves may receive inadequate support and guidance. This is an unacceptable strategic and moral oversight, one which presumably undermines the fidelity of CBT while increasing burnout: in one survey, 82% of participating supervisors expressed dissatisfaction over their support arrangements (Gabbay et al. Reference Gabbay, Kiemle and Maguire1999). Recent surveys of CBT supervisors indicate that despite an overall sense of satisfaction with supervision, considerably more can be done to support supervisors in terms of developing improved supervisory and training materials (Reiser & Milne, Reference Reiser and Milne2016). The phrase ‘something does not compute’ sums up this paradox succinctly (Watkins, Reference Watkins and Watkins1997, p. 604).

Watkins (Reference Watkins and Watkins1997) was referring to the neglect of supervisor training, but sadly there is much more than training that does not compute: the optimal organizational system for supporting and developing supervisors has ‘rarely been investigated or discussed’ (Holloway, Reference Holloway, Watkins and Milne2014, p. 612). A systemic approach seems warranted, as numerous organizational factors appear to play a part in supporting and guiding supervisors. For example, a systematic review of 24 successful supervision studies enumerated 32 contextual variables that the study authors considered had moderated effectiveness (Milne et al. Reference Milne, Aylott, Fitzpatrick and Ellis2008). Moran et al. (Reference Moran, Coyle, Boxall, Nancrow and Young2014) reviewed 43 studies where training and support interventions had been introduced. They suggested that the successful provision of supervision depended on good management relationships (e.g. role clarification), training in supervision, improvements in competence following supervision (including access to consultancy over supervision duties), good leadership (e.g. to manage clinical loads), and adequate staffing and resources.

We are delighted to introduce this Special Issue, which is a long-overdue attempt to address the question: under which organizational conditions does clinical supervision flourish? We are pleased to say that this Special Issue addresses this question thoroughly, and thank the authors for contributing. A full summary of the 10 assembled papers is provided in the final ‘discussant’ paper. These assembled papers begin with a formulation of the infrastructure problem, leading to constructive suggestions and innovative illustrations, from an international perspective. We believe that the studies and analyses that follow commence the task of ‘making things compute’, indicating how CBT supervisors can be adequately supported and guided.