5. The method of claim 4 , wherein the commonality between the instances i and j is computed by expanding respective descriptions to include one or more other concept membership statements that can be inferred based on a concept taxonomy such that information content in the commonality is a probability that a pair of random instances satisfies the pair of class membership statements in the commonality.
4. The method of claim 3 , wherein information content of the description of the instance is a probability that a random instance belongs to the virtual class.