Abstract: A similar document search method includes a step of extracting a characteristic word candidate as a candidate for a characteristic word from a seeds document including desired retrieval contents, a step of extracting as characteristic words of the seeds document, when the characteristic word candidate extracted by the extracting step is a compound characteristic word including a plurality of characteristic words, the compound characteristic word and constituent characteristic words included in the compound characteristic word from the characteristic word candidate, a step of calculating, according to the characteristic words extracted by the extracting step, similarity between the seeds document and a registration document, and a step of outputting as a retrieval result a result of the similarity calculated by the similarity calculating step.

Abstract: In the information filtering for presenting document information through the filtering using profiles as the search condition data, it is requested to urge a user to take a proper measure to obtain the result of distribution without any noise and omission at the time of information filtering by detecting existence of a plurality of similar profiles and old profiles and then notifying this fact to a user.

Abstract: Retrieval conditions inputted from a plurality of users are registered. According to the retrieval conditions, a retrieval is conducted for a text inputted. As a result of the retrieval, similarity of the text is calculated for each retrieval condition. The text is delivered to users of which the retrieval condition satisfies the similarity.

Abstract: In a text mining technique, if the system only extracts characteristic words and phrases frequently cooccurring with the respective components of an analysis axis as an analysis condition, similar words and phrases are extracted for any component. To clearly indicate existence of characteristic words and phrases which do not appear as cooccurrence words and phrases for other components of the analysis axis, it is desired to appropriately present distinguishable features between the components to the user. For this purpose, the frequency of appearances of a plurality of characteristic words and phrases in a document satisfying each analysis condition is calculated. As a result, multiple cooccurrence words and phrases and component-cooccurrence words and phrases are discriminatively displayed. It is therefore possible for the user to appropriately analyze the contents of a plurality of documents.

Abstract: A document retrieval method using a computer program includes retrieving a first set of documents using a first query expression generated by the computer program. The first set of documents is provided to a user. An evaluation of the first set of documents is received from the user. The first query expression is changed to a second query expression generated by the computer program based on the evaluation.