Correction to: Cluster identification, selection, and description in Cluster randomized crossover trials: the PREP-IT trials

An amendment to this paper has been published and can be accessed via the original article

An online general ledger system

In January 1979, the University of California Division of Library Automation (DLA) found itself with the problem of maintaining a timely, ledger. Also at that time, DLA was building a large-scale IBM operating system to support the University of California Online Union Catalog. This system also had all of the computing resources to support a sophisticated general ledger system. So, an obvious issue emerged as to whether it was more cost-effective to buy, or to write from scratch, a general ledger program. Common sense suggested that it ought to be simple to buy such software. However, exhaustive investigation revealed that flexible general ledger systems came as part of a turnkey hardware/software solution. The fact was that the IBM/370 operating system proprietary software was either mostly batch, or otherwise required costly teleprocessing software which was not a part of DLA's intended software inventory. Timesharing was considered too, but even if the right software could have been identified and located, its cost would have been greater than writing the same programs in-house. The unexpected conclusion was that it was cost-justifiable to devote a programmer's time to develop an online general ledger system that would be tailor made to DLA's needs.published or submitted for publicatio

Packet Radio for Library Online Catalogs

The advent of online catalogs in libraries has resulted in a problem that could not have been foreseen when most library buildings were built the need for wiring to transmit data between terminals and the online catalog. This problem is particularly serious in older libraries, where there are insufficient conduits, false ceilings are rare, and one faces the prospect of running cables through marble floors. Installing such wiring can be costly. The experience of the University of California demonstrates that the cost of installing terminals in quantities of eight to ten may range from $8,000 to$12,000, not including staff costs. Even if the wiring for data communications makes up only half of this figure ($4000 to$6000), it is evident that the wiring can cost as much as or more than the terminal itself.published or submitted for publicatio

Automated Turn-Key Systems in the Library: Prospects and Perils

published or submitted for publicatio