Method for comparing object ranking schemes

The present invention relates generally a method for comparing a scheme for ranking the similarity of a set of objects to a standard object, to a standard ranking scheme. One specific application is taught whereby a document image ranking scheme can be compared with a given standard ranking scheme. A method for comparing a ranking scheme for an object, such as a document image, with a known standard, or ideal ranking scheme for a comparative assessment of the performance and reliability of the two ranking schemes, is taught. The same set of objects are processed and ranked by both ranking schemes. The ranking scheme being tested is examined for all subject objects ranked lower than its ranking by the ideal ranking scheme. The test ranking scheme is charged for each swapped object which it ranked higher than the subject object, which the ideal ranking scheme ranked lower.