Several factors are involved in the decision to reclassify library collections and several problems and choices must be faced. The discussion of four classification schemes (Dewey Decimal, Library of Congress, Library of Congress subject-headings and Universal Decimal Classification) involved in the choices concerns their structure, currency, availability, flexibility, helpfulness for browsing and acceptance by the public. Problems to be considered include: possible reorganization of the cataloging effort, training or retraining personnel, effect of the change on the public service departments, initial or eventual financial economy, justification of additional expense for better service, interruption of service during reclassification, and cost and effectiveness of using an external agency. Each of these questions is examined in general and in relation to the particular systems already mentioned. The impact of the computer on library operations is examined in the context of the choice between reclassification and avoiding reclassification. The focal problems involve: the development and use of computer-produced shelf-lists, catalogs, and bibliographies and in the utilization of the results of reclassification, in computerized form, for reference service and the control of the collection. (Author/NH)