<p> Role is the super-class of all the different roles performed at a conference or workshop. Examples are the various conference chairs, the delegates, presenters, PC members, etc. The intended use of this class is that an instance of Role will be related to the event at which it is performed, and to the person which performs it. </p> <p> Since the set of roles is slightly different for each event, and since it would therefore be impossible to provide sub-classes for all needs and circumstances, the SWC ontology only contains a very basic set of Role classes. Rather than diversifying the set of Role classes to cater for all needs, users should instead instantiate the small set of different Role classes and cover the roles at a specific event in this way. E.g., instead of sub-classing the Chair role with MainChair, WorkshopChair, TutorialChair, etc., the different kinds of chairs should simply be instances of the generic Chair class and be labelled appropriately. </p>