| 摘要 |
A method for selecting a subset of content sources from a collection of content sources is disclosed. A server retrieves, in response to a plurality of queries on a topic from a client, using a programmed computer, a plurality of sets of documents from the collection of content sources. The server enumerates all subsets of the plurality of sets of documents. The server calculates, for each subset, a count of effectiveness of a subset and a price of the subset. The server selects a subset having the highest calculated ratio of count of effectiveness of the subset to price of the subset. The server delivers the selected subset of the plurality of sets of documents to the client. |
