Switching between Reasoning and Search

The crucial part of uncertain reasoning is not the process of forming a best conclusion from the facts known so far, but rather of knowing where to turn when those facts fall short. When confronted by a paradox such as the Nixon Diamond, or the Yale shooting problem, commonsense dictates that more information is required. We argue that while the concept of minimal knowledge is in some sense fundamental, adherence to it does not reflect the real world in which additional knowledge is always available. That is, knowledge outside the formal theory can always be obtained and brought to bear in decision-making. A question such as the Nixon Diamond has no ’commonsense’ solution without appealing to further relevant information. Commonsense logic systems should therefore incorporate techniques which can ’ask for more information’. This paper presents a reasoning architecture which would enable established techniques such as automated deduction to be integrated with search to provide a commonsense reasoning capability. Standard inferencing methods are enhanced by the ability to identify, seek and incorporate new knowledge needed to bring the problem solving process to a successful close. Our proposed information architecture performs problem solving in conjunction with the user by detecting inadequacies or inconsistencies in the information being used and by asking directed questions for more information when such detections are made.