The tacit dimension of expertise: Professional vision at work in airport security

Whereas "professional vision" has been mostly analyzed in apprenticeship and other settings where knowledge is made explicit or reflected upon, I focus on how expertise tacitly plays out in task-oriented interaction among practitioners. The paper considers orientation both to the coworker's (recipient design) and one's own (expressive order) expertise in the collaborative accomplishment of airport security work. I show how screeners recruit action from colleagues in largely underspecified ways, based on shared access to the visibility field and expected professional vision. Requesting is tacitly accomplished via "highlighting," which also accounts for one's request. Accepting is silently achieved via locomotion, which also serves as a display of understanding. Embodied action is systematically preferred to verbal one. Talk is employed in larger proportions when the domain of scrutiny is not equally accessible to interactants, and when "face-work" is required.