5. An information retrieval system as claimed in claim 1, wherein said history retrieval device produces a retrieval result of a current retrieval, by calculating a product set of a retrieval result of said first person in said retrieval history, and a retrieval result of a retrieval request by said second person, wherein said retrieval request by said second person is performed based upon at least one added keyword added by said second person.
1. An information retrieval system, comprising: a history storage apparatus for storing retrieval histories each having information including a group of retrieval items, a retrieval term comprised of at least one keyword, and a retrieval result; a history storage device for storing, when retrieval of documents is performed by a first person, a retrieval history regarding said retrieval into said history storage apparatus; an input device for inputting at least one of said retrieval terms by said first person and at least one of said group of retrieval items and said retrieval terms by a second person; a history retrieval device for retrieving from within said retrieval storage apparatus, a group of retrieval histories which satisfy a designation of an inputted retrieval item, said group of retrieval histories having a keyword of said retrieval term similar to an inputted keyword of said retrieval term; a similar term retrieval device for sequencing said group of retrieval histories detected by said history retrieval device based on a similarity of retrieval terms and presenting said sequenced group of retrieval histories; and a retrieval device for retrieving documents utilizing retrieval terms of a retrieval history designated by a retrieving person from within said group of retrieval histories presented by said similar term retrieval device.