The importance of semantic web resources is determined. Some resources are classes (of the type RDFS:Class); others are non-class resources. Non-class resources belong to one or more classes while class resources are subclasses of one or more parent classes. A subjectivity score is determined for each resource of a set of resources based on the number of Resource Description Format (RDF) triples of which the resource is the subject and predefined weights of properties of the triples. An objectivity score is determined for each resource based on the number of RDF triples of which the resource is the object and predefined weights of the properties of the triples. The importance of a class is determined from the respective subjectivity score and objectivity score, and a factor relating to the importance of the class's parents.