10. An apparatus for adaptive indexing of multimedia content, the comprising: a data storage system; and a data processing system coupled to the data storage system, the data processing system being configured to: identify a keyword associated with a first feature and a second feature found in a data portion of a multimedia item, the first feature being of a first media type and the second feature being of a second media type, and the first media type being associated with a first weight, and the second media type being associated with a second weight; determine a relevance for the keyword by calculating a relevance value using the first weight and the second weight; update the first weight associated with the first media type based on a search result selected by a user from a set of search results that were identified to the user in response to a query from the user to produce an updated first weight, wherein the selected search result indicates a multimedia item having a feature being of the first media type and another feature being of the second media type, each the features being associated with the keyword; updating the second weight based on a particular set of content items being identified by the selected search result to produce an updated second weight; and update the relevance of the keyword by calculating a relevance value using the updated first weight and the updated second weight.
11. The apparatus of claim 10 , wherein the first media type is one of image, sound, voice, and text.