An analysis of library use studies previously published by this author (Kilgour 1989) revealed that of every hundred user requests for a book, seven are not satisfied because the library has not acquired the book, eleven because there is a defect in the catalog or error in its use (3.45 to deficiency and 7.55 to user error), and twenty‐three because the book is not on the shelf. This paper demonstrates types of online catalog access that can reduce the failures caused by card catalog flaws or by user search errors by half.