2. In a system comprising an ASR component, the said ASR component using grammars to recognize speech in one or more interaction contexts, the said grammars comprising rules corresponding to semantic interpretations, the said rules comprising grammar components, and the said semantic interpretations organized into a semantic interpretation hierarchy, a computer-implemented method for modifying the said grammars, the said method comprising the steps of: retrieving the original grammar for the applicable interaction context from a computer-readable media; analyzing the original speech recognition grammar, wherein the said step of analyzing the said original grammar comprises: for all said semantic interpretations, analyzing the frequencies of occurrence of the grammar components within the said original grammar, the step taking into account the semantic interpretations; and for each said semantic interpretation in the said hierarchy, analyzing the frequencies of occurrence of the grammar components for all descendants of the said semantic interpretation in the said hierarchy within the original grammar; modifying the original grammar, so that the modified grammar accepts word sequences that could not be accepted by the original grammar; wherein the said step of modifying the original grammar comprises at least one of: selecting some of the said grammar components of the said original grammar and making them optional, the selection of the said components being based on the results of the said analysis step, and selecting grammar components corresponding to the said semantic interpretations in the said hierarchy and adding them to the grammar rules for their ancestors in the said hierarchy, the selection of the said components being based on the results of the said analysis step; changing a likelihood of skipping for the said grammar components of the said original grammar, the amount of change being based on the results of the said analysis step, and taking grammar components corresponding to the said semantic interpretations in the said hierarchy and adding them to the grammar rules for their ancestors in the said hierarchy, while doing this, assigning to said grammar components a likelihood of skipping, the value of which being based on the results of the said analysis step; outputting the modified grammar via computer-writable media for use by the ASR component.
3. The computer-implemented method of claim 2 , wherein the step of modifying the said original grammar further comprises at least one of: suffixing with garbage grammars these grammar components that have been added to the grammar rules of the ancestors in the said semantic interpretation hierarchy; prefixing with garbage grammars these grammar components that have been added to the grammar rules of the ancestors in the said semantic interpretation hierarchy.