INFORMATION-RETRIEVAL SYSTEMS, METHODS, AND SOFTWARE WITH CONCEPT-BASED SEARCHING AND RANKING

To improve traditional keyword based search engines, the present inventors devised, among other things, systems, methods, and software that use word co-occurrence probabilities not only to identify documents conceptually related to user queries, but also to score and rank search results. One exemplary system combines inverse-document-frequency searching with concept searching based on word co-occurrence probabilities to facilitate finding of documents that would otherwise go unfound using a given query. The exemplary system also allows ranking of search results based both on both keyword matching and concept presence, promoting more efficient organization and review of search results.