Relevance of Evidence in Bayesian Networks

For many inference tasks in Bayesian networks, computational efforts can be restricted to a relevant part of the network. Researchers have studied the relevance of a network’s variables and parameter probabilities for such tasks as sensitivity analysis and probabilistic inference in general, and identified relevant sets of variables by graphical considerations. In this paper we study relevance of the evidence variables of a network for such tasks as evidence sensitivity analysis and diagnostic test selection, and identify sets of variables on which computational efforts can focus. We relate the newly identified sets of relevant variables to previously established relevance sets and address their computation compared to these sets. We thereby paint an overall picture of the relevance of various variable sets for answering questions concerning inference and analysis in Bayesian network applications

Experiences with Modelling Issues in Building Probabilistic Networks

Abstract. Building a probabilistic network for a real-life application is a difficult and time-consuming task. Methodologies for building such a network, however, are still lacking. Also, literature on network-specific modelling issues is quite scarce. As we have developed a large proba-bilistic network for a complex medical domain, we have encountered and resolved numerous non-trivial modelling issues. Since many of these is-sues pertain not only to our application but are likely to emerge for other applications as well, we feel that sharing them will contribute to engineering probabilistic networks in general.

On Intercausal Interactions in Probabilistic Relational Models

Probabilistic relational models (PRMs) extend Bayesian networks beyond propositional expressiveness by allowing the representation of multiple interacting classes. For a specific instance of sets of concrete objects per class, a ground Bayesian network is composed by replicating parts of the PRM. The interactions between the objects that are thereby induced, are not always obvious from the PRM. We demonstrate in this paper that the replicative structure of the ground network in fact constrains the space of possible probability distributions and thereby the possible patterns of intercausal interactio