Abstract: As classical reasoning from inconsistent ontologies can’t give meaningful answers to queries, it is necessary to either revise the ontology, discarding some axioms in order to restore consistency, or make use of a non-standard notion of logical entailment that allows to give meaningful answers from inconsistent premises. We propose a complete procedure to reason with inconsistent ontologies and show how ontology revision can be obtained from inconsistency reasoning.
Abstract: \emphOntology evolution\citefgeo is the process of modifying an ontology to preserve consistency during changes. Current work on ontology evolution is based on the idea of bringing the AGM belief change theory\citeagm to work within ontology evolution. However, AGM’s principle of priority to incoming information can not be accepted when the new information represents a new evidence about the world, supposed to be a fixed static entity, while its description is only partial and uncertain. In particular, it can not be accepted in a distributed environment, where the information sources are potentially unreliable. We replace the priority to incoming information with the \emphprinciple of recoverability: any previously held piece of knowledge should belong to the current knowledge space if consistent with it.
Abstract: Ontology revision is the process of managing an ontology when a new axiom or fact would render it inconsistent. So far, the AGM approach to belief revision has been adapted to work with ontologies. However, when multiple sources are contributing uncertain knowledge about a static domain, an approach that doesn’t give priority to incoming information and allows to recover previously discarded axioms is more suited. We describe an ontology revision framework that links symbolic and numerical techniques to allow the consistent evolution of an ontology from the contributions of multiple potentially unreliable sources.
