16. A computer readable memory excluding signals tangibly encoded with a computer program executable by a processor to perform actions comprising: loading a first ontology associated with a first rule set, where an ontology is a formal representation of a set of concepts within a domain, and a set of relationships between the concepts; generating an extended ontology and an extended rule set based at least in part on the first ontology and the first rule set; applying the extended rule set to the extended ontology; determining a correctness of the extended ontology, where the correctness is a weighted measurement of errors of the ontology and where the correctness is weighted based at least in part on a type of the errors; and generating results comprising the correctness of the extended ontology.
16. A computer readable memory excluding signals tangibly encoded with a computer program executable by a processor to perform actions comprising: loading a first ontology associated with a first rule set, where an ontology is a formal representation of a set of concepts within a domain, and a set of relationships between the concepts; generating an extended ontology and an extended rule set based at least in part on the first ontology and the first rule set; applying the extended rule set to the extended ontology; determining a correctness of the extended ontology, where the correctness is a weighted measurement of errors of the ontology and where the correctness is weighted based at least in part on a type of the errors; and generating results comprising the correctness of the extended ontology. 20. The computer readable memory of claim 16 , where the first rule set is configured in accordance with a sematic web rule language.