How to use Nepomuk Ontologies

The Nepomuk Ontologies are:

• www.semanticdesktop.org/ontologies - overview of all ontologies
• PimoOntology - frequently asked questions at PimoFaq
• NieOntology
• FreditOntology
• ObjectRankOntology
• Search Engine for all NEPOMUK Ontologies including PIMO

Adding Ontologies to a Semantic Desktop

If your application requires an ontology to be present in the RDF store, you should check during installation or during application startup, if the ontology is present. If not, best practice is to add the ontology. Do not rely on ontologies being present, PimoService will ensure that the core ontologies RDF, RDFS, NRL, NAO, and PIMO are, but not much more. PimoService does this the way any other service should do: by checking the existence of the ontologies during startup.

Unsure how this works? Use the ontology methods provided by PimoService.

Limited Inference and Queries

NEPOMUK in the java version supports a-box limited inferencing. Instead of asking "?x rdf:type pimo:Person" you have to use "?x rdf:type ?t. ?t rdfs:subClassOf pimo:Person". please read on about the pecularities of Queries:

• NepomukInferencing

Philosophical FAQ about NIE

In the picture on containment in NIE (see section on information elements), nie:hasPart seems for me to correspond to "contains". Is this correct?

Yes, an InformationElement contains a DataObject. This is expressed using a hasPart triple: IE hasPart DO..

And nie:isStoredAs would be between Message and MailboxDataObject for example, right?

Yes, nie:isStoredAs links the information element with the DataObject it is stored in.