Cyc: A Mid-Term Report

Abstract After explicating the need for a large common-sense knowledge base spanning human consensus knowledge, we report on many of the lessons learned over the first five years of attempting its construction. We have come a long way, in terms of methodology, representation language, techniques for efficient inferencing, the ontology of the knowledge base, and in terms of the environment and infrastructure in which it is being built. We describe the evolution of Cyc, its current state, and close with a look ahead at our plans and expectations for the coming five years, including an argument for how and why the project may conclude at that time.