Describes a project at the University of Sheffield that is investigating the use of nearest-neighbor retrieval algorithms for full-text searching. Nearest-neighbor searching is compared with Boolean retrieval and hypertext, and an experimental text retrieval system called INSTRUCT (Interactive System for Teaching Retrieval Using Computational…

Describes the unique reliability problems of very large databases that necessitate specialized techniques for hardware problem management. The discussion covers the use of controlled partial redundancy to improve reliability, issues in operating systems and database management systems design, and the impact of disk technology on very large…

Evaluates and compares two recently proposed automatic methods for relevance feedback of Boolean queries (Dillon method, which uses probabilistic approach as basis, and disjunctive normal form method). Conclusions are drawn concerning the use of effective feedback methods in a Boolean query environment. Nineteen references are included. (EJS)