Basic Research in Knowledge Representation

Abstract : This project concerned developing new logical formalisms for representing information. New formalisms allow us to represent information that we previously could not capture. New reasoning methods allow us to integrate more information and can yield conclusions that were previously unavailable. One basic method that was developed involves introducing contexts as mathematical objects and developing formal language for describing the relations between sentences true in different contexts. This allows information that arose from different sources to be integrated, taking account of the differences in collection methodologies, uncertainties, differing languages and ontologies, and potential inconsistencies. The other main thrust was to describe the processes that underly the changes that occur when new information arrives. The representation of counterfactuals, change, and defeasible reasoning was studied. Each of these allow us to capture how new information should make us adjust our current view of the world.