In planning and design, engagement projects often involve community meetings and charrattes, and we have some ideas about how to stimulate participation and get people really engaged in conversations and actions. Is there a survey or scale that can measure the success or effectiveness of the meetings? Say, if we randomly assign people to two meetings aiming at discussing design solutions for a regeneration project, one with maps, trace paper, stickers, pictures and one with only maps. How can we tell if the former one is more effective than the latter?