An opportunistic reasoning system may combine elements of both forward and backward reasoning. It is useful when the number of possible inferences is very large and the reasoning system must be responsive to new data that may become known.[2]
Opportunistic reasoning has been used in applications such as blackboard systems and medical applications.[3]
References
Marin D. Simina et al. "Opportunistic Reasoning: A Design Perspective" in Proceedings of the Seventeenth Annual Conference of Cognitive Science edited by Johanna D. Moore, 1995 ISBN0-8058-2159-7, page 78