1. A method for determining a set of keywords associated with a document, comprising: receiving a document to classify into a taxonomy, the taxonomy including a plurality of categories, each category of the plurality of categories being represented by a concatenation of a corresponding set of documents; receiving a categorization ranking for each category of the plurality of categories for the received document; determining a set of categories of the taxonomy having highest categorization rankings of the plurality of categories for the received document; combining together the documents representing the categories of the determined set of categories within the taxonomy into a cumulative representative text that includes a plurality of terms; determining a cumulative term corpus importance score for each term in the cumulative representative text, the cumulative term corpus importance score for a particular term indicating an importance of the particular term in a context of the cumulative representative text; and selecting a set of terms of the cumulative representative text having highest cumulative term corpus importance scores of the plurality of terms.