in assigning features to nodes of a tree structured classifier and determining terminal nodes in response to a training set of objects each being determined by a plurality of features , a selected characteristic , such as a cost function based on the minimum description length , of the plurality of features unused at prior nodes is determined along the path from the root to the present node , a feature is then assigned to the node having a preferred value for the selected characteristic relative to the other features . child nodes of the node are created in response to the assigned feature with features assigned thereto in a similar way . the preferred values for the selected characteristics of the assigned features for the child nodes of the node are combined and compared with the preferred value of their father node . classification of the father node as a terminal is based upon such a comparison .