1988 Volume 31 Issue 2 Pages 117-126
Nowadays everyone can enjoy an information retrieval, thanks for the advancement of computer usage in searching the literatures of science and technology. Regarding limitation for database usage in these days, the author divided searchers into four generations according to their skillful degree for the retrieval technics. In this paper, the author considered a blind spot from the view point of retrieval by searcher after the third generation, who started to have a suspicion to the content of database and emphasised the following three blind spots that we cannot aford to overlook, 1) limitation on input to database, 2) limitation of keyword and code search computer searching, 3) limitation on fitness evaluation of retrieved results.