• Evidence-based public health
• research agendas
• protocols
• scientific progress

Petticrew, Chalabi and Jones have made some of the most vibrant and erudite contributions to the methodology of healthcare research. Their ‘To RCT or not to RCT’1 paper marks another significant contribution. I recommended it for publication in the journal—adding as an aside in my referee's comments that I happened to disagree with every word. The editors have been kind enough to offer me a little space to air these thoughts.

Petticrew and colleagues pose a question with immense scientific, policy and financial implications—how to decide upon the future research agenda? The answer is provided in terms of a ‘decision flow chart’—following the proposed assessment pathways is said to enable research commissioners to make wiser judgements. It is a clearly and engagingly written piece. In its own terms and that of much current thinking in evidence-based public health, it makes a valuable contribution. From the perspective of this commentary, it marks a further embrace of the highly proceduralised view of enquiry that is common in the health sciences. We have protocols for designing trials, protocols for conducting systematic reviews, and now an agenda-setting protocol to determine where and what further research is needed. I want to argue that such a ‘follow-the-formula’ perspective is at odds with both the realpolitik of policy making and the manner in which scientific explanations extend and develop.

Let us begin with the decision makers and the decision used in the illustrative case—whether we need a new RCT to evaluate the impact of allowing motorcyclists to use bus lanes in London. By the standards and …