1. A method comprising: (a) calculating estimated weights for identified errors in recognition of utterances of a speaker based on a reference string, the utterances being received by a speaker input and converted to digital signals; (b) marking sections of the utterances as being misrecognized and associating the estimated weights with the sections of the utterances; and (c) using the weighted sections of the utterances to convert a speaker independent model to a speaker dependent model; wherein calculating the estimated weights comprises computing an average likelihood difference per frame and then computing a weight value by averaging the average likelihood difference over error words.