The error-correcting algorithm described was constructed to examine subject headings in online catalog records for common errors such as omission, addition, substitution, and transposition errors, and to make needed changes. Essentially, the algorithm searches the authority file for a record whose primary key exactly matches the test key. If an…

Addressing the problem of protecting confidential information and data stored in computer databases from access by unauthorized parties, this paper details coding schemes which present such astronomical work factors to potential code breakers that security breaches are hopeless in any practical sense. Two procedures which can be used to encode for…

Describes a computerized information retrieval system that uses three agglomerative hierarchic clustering algorithms--single link, complete link, and group average link--and explains their implementations. It is noted that these implementations have been used to cluster a collection of 12,000 documents. (LRW)

Using macro and micro-structure analysis of large files of personal author names, this study developed retrieval techniques and algorithms to automatically correct and/or flag typographical errors in names, identify names in a database that are similar to a name entered by a user during a search, and measure similarities between names. It was…

Presents a mathematical theory that can be used to define concentration places of objects within unordered classes. The application to research on the evolution of journals and subject areas is illustrated, and an online method of calculating concentration evolution is described. (1 references) (CLB)

Discusses the problem of duplicate citations resulting from file overlaps in multidatabase searching and shows that such duplicates could be identified automatically and eliminated by a host computer as a complementary service to online retrieval. Steps involved in the realization of this service are described, and 11 references are listed. (RBF)

Discussion of a new method of index term dictionary compression in an inverted-file-oriented database highlights a technique of word coding, which generates short fixed-length codes obtained from the index terms themselves by analysis of monogram and bigram statistical distributions. Substantial savings in communication channel utilization are…

The Hepatitis Knowledge Base (text of prototype information system) was used for modifying and testing "A Navigator of Natural Language Organized (Textual) Data" (ANNOD), a retrieval system which combines probabilistic, linguistic, and empirical means to rank individual paragraphs of full text for similarity to natural language queries…

Analytical methods for facilitating comparison of multiple sets during online searching are illustrated by description of specific searching methods that eliminate duplicate citations and a factoring procedure based on syntactic relationships that establishes ranked sets. Searches executed in National Center for Mental Health database on…

Describes a two-phase stemming algorithm which consists of word root identification and automatic selection of word variants starting with same word root from inverted file. Use of algorithm in book catalog file is discussed. Ten references and example of subject search are appended. (EJS)

Presents an algorithm for use in natural language document retrieval systems which automatically determines if the conjunction "and" in a statement representing an information need should be translated into a Boolean "and" or "or." The results of an experiment that used the algorithm are reported, and further research is suggested. (CLB)