1. A computer executable method for determining metadata to be assigned to a document, the method comprising: identifying a document to be published to a collection of documents organized according to a predetermined taxonomy sanctioned by an organization independent of an entity that controls the collection of documents and that includes a stored plurality of predetermined knowledge categories; applying a trained text classifier to the identified document; outputting from the trained text classifier at least one of the plurality of predetermined knowledge categories; without parsing the document into predicate structures, automatically presenting to a user the at least one of the plurality of predetermined knowledge categories that is output by the trained text classifier as at least one recommended knowledge category for the user to select to publish the document to the collection of documents; receiving, from the user, a selection of at least one knowledge category for the document; expanding a knowledge category to at least one related knowledge category, wherein the at least one related knowledge category is within a hierarchy in the predetermined taxonomy of categories including the at least one recommended knowledge category; receiving, from the user, a selection of at least one related knowledge category for the document; and assigning the at least one selected knowledge category and the at least one related knowledge category as metadata for publishing the document to the collection of documents.