Ontologies and Metadata Formats

Ontologies and shared vocabularies are essential in developing distributed technologies. Which vocabularies can support typical tasks of ES algorithms?
Do we need a Social-Networks Ontology?
Do we need a Uncertain Ontology? (see uncertainty ontology W3C: http://www.w3.org/2005/Incubator/urw3/group/draftReport.html)

Social Networks

Le me signal this paper proposing a model that extend the traditional bipartite model of ontologies with the social dimension, leading to a tripartite model of actors, concepts and instances.