Chapter 11 - Basic OWL

Abstract

This chapter presents the modeling capabilities of Web Ontology Language (OWL) that go beyond RDFS-Plus. A key functionality of OWL is the ability to define restriction classes. The unnamed classes are defined based on restrictions on the values for particular properties of the class. Using this mechanism, OWL can be used to model situations in which the members of a particular class must have certain properties. In RDFS, the domain and range restrictions can allow one to make inferences about all the members of a class (such as plays relating a baseball player to a team). In OWL, one can use restriction statements to differentiate the case between something that applies to all members of a class versus some members, and even to insist on a particular value for a specific property of all members of a class. When restrictions are used in combination with the constructs of RDFS, and then they are cascaded with one another, they can be used to model complex relationships between properties, classes, and individuals. The advantage of modeling relationships in this way (over informal specification) is that interactions of multiple specifications can be understood and even processed automatically.