The challenge of participatory approaches, imho, can be well described using the terms Goffman builds with in this chapter: sincerity vs cynicism, reality & contrivance, convincing others & conviction in one's role, command of an idiom.
Contemporary designers, particularly those working in experience led pursuits, play a more epistemic role than they used to. They still make things, but more and more these artifacts are created to facilitate understanding & construct knowledge. To do this they will contrive design situations, with an idiomatic command of actions and artifacts that render these contrivances convincing.
