Systems and methods are provided for classifying a search query. A first group of query classifiers can be used to evaluate a query relative to various subject matter domains. The evaluation results from the first group of domain classifiers can then be used by a second group of meta-classifiers. The meta-classifiers are based on non-linear classification models. The meta-classifiers are associated with meta-classifier categories that may correspond to a domain or that may correspond to a plurality of domains. The assigned meta-classifier category for a query can be used in any convenient manner, such as by triggering additional uses of the search query to match images or other alternative types of documents, or such as by allowing a subject matter domain to be assigned to the query.