A Sparse Bayesian Compression Scheme — The Informative Vector Machine
Kernel based learning algorithms allow the mapping of data-set into an infinite dimensional feature space in which a classification may be performed. As such kernel methods represent a powerful approach to the solution of many non-linear problems. However kernel methods do suffer from one unfortunate drawback, the Gram matrix contains m rows and columns where m is the number of data-points. Many operations are therefore precluded (e.g. matrix inverse $O(m^3)$) when data-sets containing more than about $10^4$ points are encountered. One approach to resolving these issues is to look for sparse representations of the data-set A sparse representation contains a reduced number of examples. Loosely speaking we are interested in extracting the maximum amount of information from the minimum number of data-points. To achieve this in a principled manner we are interested in estimating the amount of information each data-point contains. In the framework presented here we make use of the Bayesian methodology to determine how much information is gained from each data-point.