Abstract
This paper discusses—from a European point of view—the likely arguments in favour of, and in opposition to, the use of private file services currently offered by online information-retrieval vendors and computer companies. After reviewing the nature of private file applications and users, the author deals at some length with the question of costs—for storage and connect time, and for telecommunication. Costs are compared for a standard case, based on one month's library usage of a private file on four different hosts: Data Star, IRS-ESA, Lockheed Dialog, and Questel. After then discussing the factor of usage level in cost determination, and some criteria for deciding whether or not to enter upon a private file arrangement, the author describes in particular the chemical substructure search systems of CAS and Questel (DARC) in terms of their private file offerings, and then considers the question of data confidentiality. There follows an account of the steps which one should take before implementing a private file in regard to record structure and format, as well as file loading and updating, and of the considerations involved in deciding whether or not to make use of a private file service.