3. In a computing environment, a system comprising: a category selection mechanism coupled to an intermediate taxonomy and a target taxonomy and configured to select a subset of intermediate taxonomy categories represented in the intermediate taxonomy based on relevance to target taxonomy categories represented in the target taxonomy, wherein the category selection mechanism is configured to compute the relevance based on relative probability scores between the intermediate taxonomy categories and the target taxonomy categories, individual relative probability scores corresponding to a probability of a corresponding intermediate taxonomy category generating one or more of the target taxonomy categories; a taxonomy bridging mechanism configured to process the subset of intermediate taxonomy categories to construct a bridging classifier for use in relating online queries to individual target taxonomy categories in the target taxonomy, the taxonomy bridging mechanism configured to determine relationship values between one or more of the intermediate taxonomy categories and one or more of the target taxonomy categories to construct the bridging classifier a computing device configured to implement at least one of the category selection mechanism or the taxonomy bridging mechanism.
3. In a computing environment, a system comprising: a category selection mechanism coupled to an intermediate taxonomy and a target taxonomy and configured to select a subset of intermediate taxonomy categories represented in the intermediate taxonomy based on relevance to target taxonomy categories represented in the target taxonomy, wherein the category selection mechanism is configured to compute the relevance based on relative probability scores between the intermediate taxonomy categories and the target taxonomy categories, individual relative probability scores corresponding to a probability of a corresponding intermediate taxonomy category generating one or more of the target taxonomy categories; a taxonomy bridging mechanism configured to process the subset of intermediate taxonomy categories to construct a bridging classifier for use in relating online queries to individual target taxonomy categories in the target taxonomy, the taxonomy bridging mechanism configured to determine relationship values between one or more of the intermediate taxonomy categories and one or more of the target taxonomy categories to construct the bridging classifier a computing device configured to implement at least one of the category selection mechanism or the taxonomy bridging mechanism. 5. The system of claim 3 wherein the category selection mechanism operates in an offline state relative to the taxonomy bridging classifier relating the online queries to the individual target taxonomy categories in the target taxonomy.