9. A computer system for generating a recognition data model set comprising: one or more processors, one or more computer-readable memories, and one or more computer-readable, tangible storage devices; program instructions, stored on at least one of the one or more computer-readable, tangible storage devices for execution by at least one of the one or more processors via at least one of the one or more computer-readable memories, to base a first group of class dependent data models sets on a second group of corresponding class dependent training data sets, each set of training data originating from a subset of all training data; program instructions, stored on at least one of the one or more computer-readable, tangible storage devices for execution by at least one of the one or more processors via at least one of the one or more computer-readable memories, to base a class independent data model set on all training data, each data model set comprising a plurality of data models, wherein each data model in a data model set is part of one group of corresponding data models from other data model sets; program instructions, stored on at least one of the one or more computer-readable, tangible storage devices for execution by at least one of the one or more processors via at least one of the one or more computer-readable memories, to compare a fit of each group of corresponding class dependent data models to training data and the fit of a corresponding independent data model to all the training data, wherein the fit is determined by measuring a difference between a first cross entropy of corresponding class dependent data models and the training data and a second cross entropy of a corresponding class independent data model and the training data; program instructions, stored on at least one of the one or more computer-readable, tangible storage devices for execution by at least one of the one or more processors via at least one of the one or more computer-readable memories, to add, responsive to determining that a difference between the first cross entropy and the second cross entropy is insignificant, the corresponding class independent data model to a final data model set; and program instructions, stored on at least one of the one or more computer-readable, tangible storage devices for execution by at least one of the one or more processors via at least one of the one or more computer-readable memories, to add, responsive to determining that the difference between the first cross entropy and the second cross entropy is significant, the corresponding class dependent data models to the final data model set.
12. The computer system according to claim 9 wherein three or more class dependent data model sets are used.