Abstract

An information storage/retrieval system stores information to be retrieved in a storage device having a first memory and a second memory. The first memory stores therein main records each containing an index word data, a derivative pattern code and information pieces while the second memory stores therein auxiliary records each containing a derivative pattern code and supplemental word data. Each derivative pattern code represents a group of words whose primary parts such as word stem parts are commonly combinable with the same remaining parts such as affix parts. Thus, each index word data is qualified by the accompanying derivative pattern code, and the supplemental word data includes data corresponding to the above-mentioned remaining parts. An information retrieval is made by searching in a first memory with respect the primary part of a keyword taken from, for example, its head and then in a second memory with respect to the remaining part of the keyword, thereby identifying the keyword. Relevant information to be outputted is found in at least one of the first and second memories on the basis of a supplmental word data in the second memory.