Building Bayesian Network Models in Medicine: The MENTOR Experience

摘要

An experiment in Bayesian model building from a large medical dataset for Mental Retardation is discussed in this paper. We give a step by step description of the practical aspects of building a Bayesian Network from a dataset. We enumerate and briefly describe the tools required, address the problem of missing values in big datasets resulting from incomplete clinical findings and elaborate on our solution to the problem. We advance some reasons why imputation is a more desirable approach for model building than some other ad hoc methods suggested in literature. In our experiment, the initial Bayesian Network is learned from a dataset using a machine learning program called CB. The network structure and the conditional probabilities are then modified under the guidance of a domain expert. We present validation results for the unmodified and modified networks and give some suggestions for improvement of the model.