Abstract
This paper introduces the concept of transactional design---integrating Druschke's "transactional" model of rhetoric and science and Kinsella's model of "public expertise"---to demonstrate how technical communication and user experience (UX) designers and researchers can play an essential role in helping scientists cultivate meaningful relationships with members of the public toward the goal of making scientific content more accessible and actionable. This paper reports on the challenges that arose when a water modeling system built for experts was adapted for a public museum audience. It discusses specific issues the UX team had in contending with outdated "deficit" and "conduit" models of communication when working with scientists to adapt the system; it provides a checklist for steps that technical communication and UX designers and researchers---as those who best understand audiences and work directly with users---can champion the idea of transactional design to setup knowledge-making partnerships toward the co-construction of public-facing scientific communication projects.