20. The computer-readable storage device of claim 17 , wherein the new sequence of tags comprises tags from a predefined set of tags relating to different types of named entities.
17. A computer-readable storage device having instructions stored which, when executed by a computing device, cause the computing device to perform operations comprising: operating a natural language understanding application with a statistical model that generates a first sequence of tags assigned to a sequence of words; developing a first part without human knowledge, the first part being first data used to formulate a replacement statistical model; developing a second part using the human knowledge and annotated words, the second part being a second data used to formulate the replacement statistical model; assigning weighted versions of the first part and the second part to yield the replacement statistical model, wherein the weighted version are determined based on an amount of annotated data that is available; and during execution of the natural language understanding application in which a second sequences of words is received as speech for processing using the natural language understanding application, assigning a new sequence of tags to the second sequence of words, the new sequence of tags being generated by the replacement statistical model.