Systems and methods for performing electronic information retrieval

摘要

System and methods for identifying output documents similar to an input document. A query is formulated using a list of best keywords from the input document to search for a first set of output documents. The list of best keywords is defined with a maximum number of keywords less than the total number of keywords in the list of best keywords that are identified as belonging to a domain specific dictionary of words and as having no measurable linguistic frequency. Lists of keywords are identified for each output document in the first set of documents. A second set of similar documents is determined using a measure of similarity that is computed between keywords identified in the input document and each output document in the first set of documents. In addition, a measure of similarity between two documents is computed. In computing the measure of similarity, a first list of rated keywords extracted from the first document and a second list of rated keywords extracted from the second document are received. The first and second lists of keywords are used to determine whether the first document forms part of the second document using a first computed percentage indicating what percentage of keyword ratings in the first list also exist in the second list. A second percentage is computed that indicates what percentage of keyword ratings along with a set of their neighboring keyword ratings in the first list that also exist in the second list when the first percentage indicates that the first document is included in the second document. The first percentage is used to specify the measure of similarity when the second percentage is greater than the first percentage.