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
• L3SOntology
•  Search Engine for all NEPOMUK Ontologies including PIMO

For information about pending changes to ontologies, feedback on bugs in ontologies, and our ontology maintenance process, refer to OntologyMaintenance.

FAQ on ontologies

I found a bug in ontology X…

Refer to OntologyMaintenance for the list of known bugs and ways how to contact the ontology developers. The ontologies are maintained by the  OSCA-Foundation

URIs in NEPOMUK

URIs are used to identify several different data sources and different types of elements. A page about URIs sums up all our decisions:

• RecommendedUris

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.

Adding Data to a Semantic Desktop

The best way to add PIMO data is to use the methods of PimoService.

For extracted resources, refer to RecommendationStoringInformationElements

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.