Exterior / Outward Participation
Doing all the people’s parts:
praying, singing, responding, processing, listening, standing, sitting, kneeling, shaking hands, eating, drinking etc.
 
Participation (cont.)
Exterior participation is that which can be observed. We participate by doing all of the parts assigned to the people, such as praying, singing, responding, processing, listening, standing, sitting, kneeling, shaking hands, eating, drinking…

Note that participation in the verbal parts was facilitated after Vatican II because the liturgy began to be celebrated in English.