System and method for determining numerical representations for categorical data fields and data processing system

A system and method execute search and retrieval techniques relative to previously stored documents or other objects. The system generally comprises a terminal and a server. The terminal requests the server to perform a preparation search based on a search term before requesting the extended search. The designated document is a document selected from a result of the preparation search. The server stores as a selection history the search term used in the preparation search along with the retrieval result. In addition, the system determines a selection frequency for each document that is measured with respect to selected documents with which it is retrieved. The present method conducts a first search based on key words or phrases, receives the selection of a given document relative to a result of the first search, and then conducts a second search based on the selected given document. If in the second search the given document was extracted in a previous retrieval process made by a user, a document having a history of being selected concurrently with the given document is extracted. Any document concurrently selected by the user with respect to the document extracted in the second search is automatically stored and noted as being associated with the search request.