Toward Normative Expert Systems: Part II Probability-Based Representations for Efficient Knowledge Acquisition and Inference. Heckerman, D. E & Nathwani, B. N Methods of Information in Medicine, 1992.
abstract   bibtex   
We address practical issues concerning the construction and use of decision-theoretic or normative expert systems for diagnosis. In particular, we examine Pathfinder, a normative expert system that assists surgical pathologists with the diagnosis of lymph-node diseases, and discuss the representation of dependencies among pieces of evidence within this system. We describe the belief network, a graphical representation of proba-bilistic dependencies. We see how Pathfinder uses a belief network to construct differen-tial diagnoses efficiently, even when there are dependencies among pieces of evidence. In addition, we introduce an extension of the belief-network representation called a similarity network, a tool for constructing large and complex belief networks. The rep-resentation allows a user to construct independent belief networks for subsets of a given domain. A valid belief network for the entire domain can then be constructed from the individual belief networks. We also introduce the partition, a graphical representation that facilitates the assessment of probabilities associated with a belief network. Finally, we show that the similarity-network and partition representations made practical the construction of Pathfinder.
@article{heckerman_toward_1992,
	title = {Toward {Normative} {Expert} {Systems}: {Part} {II} {Probability}-{Based} {Representations} for {Efficient} {Knowledge} {Acquisition} and {Inference}},
	abstract = {We address practical issues concerning the construction and use of decision-theoretic or normative expert systems for diagnosis. In particular, we examine Pathfinder, a normative expert system that assists surgical pathologists with the diagnosis of lymph-node diseases, and discuss the representation of dependencies among pieces of evidence within this system. We describe the belief network, a graphical representation of proba-bilistic dependencies. We see how Pathfinder uses a belief network to construct differen-tial diagnoses efficiently, even when there are dependencies among pieces of evidence. In addition, we introduce an extension of the belief-network representation called a similarity network, a tool for constructing large and complex belief networks. The rep-resentation allows a user to construct independent belief networks for subsets of a given domain. A valid belief network for the entire domain can then be constructed from the individual belief networks. We also introduce the partition, a graphical representation that facilitates the assessment of probabilities associated with a belief network. Finally, we show that the similarity-network and partition representations made practical the construction of Pathfinder.},
	journal = {Methods of Information in Medicine},
	author = {Heckerman, David E and Nathwani, Bharat N},
	year = {1992},
}

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