Systems practitioners often make significant claims for the value of their methodologies and methods. However, when evidence is presented to support these claims, it is usually based solely on the practitioner’s own reflections on single case studies. Less often, practitioners set up post-intervention debriefings with project participants using questionnaires. While the latter is an improvement on researcher reflections alone, there have been few attempts at systematically evaluating across methods and across case studies undertaken by different practitioners. This is understandable because, in any given local intervention, contextual factors, the skills of the practitioner and the purposes being pursued by stakeholders are inevitably going...