Bayesian Metanetwork for Context-Sensitive Feature Relevance
Bayesian Networks are proven to be a comprehensive model to describe causal relationships among domain attributes with probabilistic measure of appropriate conditional dependency. However, depending on task and context, many attributes of the model might not be relevant. If a network has been learned across multiple contexts then all uncovered conditional dependencies are averaged over all contexts and cannot guarantee high predictive accuracy when applied to a concrete case. We are considering a context as a set of contextual attributes, which are not directly effect probability distribution of the target attributes, but they effect on a “relevance” of the predictive attributes towards target attributes. In this paper we use the Bayesian Metanetwork vision to model such context-sensitive feature relevance. Such model assumes that the relevance of predictive attributes in a Bayesian network might be a random attribute itself and it provides a tool to reason based not only on probabilities of predictive attributes but also on their relevancies. According to this model, the evidence observed about contextual attributes is used to extract a relevant substructure from a Bayesian network model and then the predictive attributes evidence is used to reason about probability distribution of the target attribute in the extracted sub-network. We provide the basic architecture for such Bayesian Metanetwork, basic reasoning formalism and some examples.
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- 2.Henrion, M.: Some Practical Issues in Constructing Belief Networks. In: Proceedings of the 3rd Annual Conference on Uncertainty in Artificial Intelligence, pp. 161–174. Elsevier, Amsterdam (1989)Google Scholar
- 3.Heckerman, D.: A Tutorial on Learning with Bayesian Networks, Technical Report MSR-TR-95-06, Microsoft Research (March 1995)Google Scholar
- 4.Butz, C.J.: Exploiting Contextual Independencies in Web Search and User Profiling. In: Proc. of the World Congress on Computational Intelligence, Hawaii, USA, pp. 1051–1056 (2002)Google Scholar
- 5.Boutiler, C., Friedman, N., Goldszmidt, M., Koller, D.: Context-Specific Independence in Bayesian Networks. In: Proceedings of the 12th Conference on Uncertainty in Artificial Intelligence, Portland, USA, pp. 115–123 (1996)Google Scholar
- 13.Terziyan, Vitko, O.: Learning Bayesian Metanetworks from Data with Multilevel Uncertainty. In: Bramer, M., Devedzic, V. (eds.) Proc. of the First IFIP International Conf. on Artificial Intelligence and Innovations, Toulouse, France, pp. 187–196. Kluwer, Dordrecht (2004)Google Scholar