Distribution of mutual information from complete and incomplete data
- 作者：Hutter ; Marcus ; Zaffalon ; Marco
- 关键词：Dirichlet distribution ; Expectation and variance of mutual information ; Feature selection ; Filters ; Naive Bayes classifier ; Bayesian statistics
- 刊名：Computational Statistics and Data Analysis
- 出版年：2004
- 期刊代码：19_01679473
- 类别：cp
- 出版时间：March 1, 2004
- 卷：48
- 期：3
- 页码：633-657
- 文件大小：409 K
摘要
Mutual information is widely used, in a descriptive way, to measure the stochastic dependence of categorical random variables. In order to address questions such as the reliability of the descriptive value, one must consider sample-to-population inferential approaches. This paper deals with the posterior distribution of mutual information, as obtained in a Bayesian framework by a second-order Dirichlet prior distribution. The exact analytical expression for the mean, and analytical approximations for the variance, skewness and kurtosis are derived. These approximations have a guaranteed accuracy level of the order O(n−3), where n is the sample size. Leading order approximations for the mean and the variance are derived in the case of incomplete samples. The derived analytical expressions allow the distribution of mutual information to be approximated reliably and quickly. In fact, the derived expressions can be computed with the same order of complexity needed for descriptive mutual information. This makes the distribution of mutual information become a concrete alternative to descriptive mutual information in many applications which would benefit from moving to the inductive side. Some of these prospective applications are discussed, and one of them, namely feature selection, is shown to perform significantly better when inductive mutual information is used.