Search engine and method with improved relevancy, scope, and timeliness

摘要

A search engine and a method achieve timeliness of documents returned in a search result by a relevancy feedback mechanism driven by the frequency in which a URL is returned in recent searches. The relevancy feedback mechanism includes one or more random processes which determine whether or not a cached or indexed web page associated with a URL in the search result should be refreshed. In addition, the random processes also determine whether or not hyperlinks in the cached or indexed web page should be followed to access related web pages. Accesses of web pages resulting from the operations of the random processes are used to update any document index maintained by the search engine. Relevancy scoring functions implemented in look-up tables are also disclosed. A more accurate relevancy scoring function is achieved using a lexicon based on anchortexts of extracted hyperlinks of web documents.