Which techniques and skills can be used to overcome the obstacle of dialogue between scientists in different disciplines? Drawing on Gorman's book on trading zones and Collins and Evans' thinking on interactional expertise, this article analyses the work by individuals to manage five interdisciplinary panels commissioned by French ministries. It observes that these panel managers have different techniques to open, construct and close the debate. These techniques, which condition the submission of the final report, call for skills that managers acquire over the course of their experiences in trading zones. Implications of findings for the formation and management of interdisciplinary expert groups and for the concept of interactional expertise are discussed.