
228 Analyzing and Securing Social Networks
19.3.6 Modeling acTions
In a social network, actions are the basis of user participation. According to the proposed represen-
tation, an action is dened as an object property that relates users, resources, and actions. Moreover,
we model hierarchies for actions by means of subproperty. Take, for instance, three generic actions:
Read, Write, and Delete. We dene a hierarchy in which Delete is a subtype of Write, which is,
itself, a subtype of Read. In a nonhierarchical model, if John Smith was able to read, write, and
delete a photo, then we would need three authorizations to represent this propert