Information search system

Abstract

An information search system, including: a database (); a query sentence acceptance unit () that accepts a query sentence; an inputted search keyword extractor () that extracts an inputted search keyword from the query sentence; a shared keyword dictionary () in which relevant keywords are registered in association with each other; a local keyword dictionary () in which district keywords used in particular districts are registered; a candidate search keyword reader () that reads out a keyword that is relevant to the inputted search keyword; and a retrieval executor () that executes retrieval processing from the database using the inputted search keyword, wherein, in a case in which the inputted search keyword is not registered in the local keyword dictionary, the candidate search keyword reader refers to the shared keyword dictionary, so as to read out a keyword that is relevant to the inputted search keyword.