Institutions are the constructions in society within which coordinated activity is carried on. Within them actions are considered and certain roles are in existence or are brought into existence to focus these actions. Roles are appropriate sets of actions. They have existence over and beyond the lives and abilities of their incumbents. They can be or 'played'. They may be formulated, such as the role of juror on a jury, or left very open, such as the role of conjurer or hitch-hiker, to which few rules apply.