摘要:

AbstractSince the introduction of the Zipf distribution, many functions have been suggested for the frequency of words in text. Some of these models have also been applied to the distribution of index terms in a set of documents. The models are of two forms: rank‐frequency and frequency‐size. The former serve well to describe the distribution of high‐frequency terms; the latter the distribution of low‐frequency terms. In this article, a split model is proposed, which uses both a rank function for the high frequency terms and a size function for the low frequency terms, with the point of transition being determined either empirically or by rule. This model is fitted to the marginal empirical term distributions for four document datasets. Distributions to describe index term exhaustivity and term co‐occurrence are also considere

ISSN:0002-8231    

DOI:10.1002/asi.4630360502

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractU.S. patents (and the technology they represent) age and eventually become obsolete. In this diachronous study, the citations by patents in a given year are compared to the number in subsequent years. The major findings are that, even though influential patents remain influential as they age, both highly and infrequently cited patents age at the same rate. This means that citations do not automatically beget more citations, and without this bandwagon effect, no patents are enduring. In addition, the distribution of patents by number of citations received is stable over time (here, in each year they are distributed as a negative binomial).

ISSN:0002-8231    

DOI:10.1002/asi.4630360503

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractPerceived accessibility to information is proposed as a unifying concept for the design and evaluation of a wide variety of information systems and services. This field study measured end‐user perceptions of three sources of information (computer‐based, libraries, and individuals) for three samples of individuals. The results suggest that 1) accessibility is a multidimensional concept encompassing physical access to the source, the interface to the source, and the ability to physically retrieve potentially relevant information, and 2) perceptions of accessibility are moderated by prior experience with the source and contextual fact

ISSN:0002-8231    

DOI:10.1002/asi.4630360504

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractScientific publishing has evolved over three centuries of technological change. It now faces problems that include rapid growth, literature scatter, increasing costs, and excessive delays in publication. This article examines technical solutions to increasing delays and costs and explores new ways of disseminating research information. Noting developments in computer networking and microcomputer applications, the author contends that the widespread use of personal computers will accelerate the development of electronic publishing.

ISSN:0002-8231    

DOI:10.1002/asi.4630360505

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe Generalized Inverse Gaussian‐Poisson Distribution is suggested as an all‐embracing mathematical model for bibliometric frequency distributions. Twelve examples are given which show that the new model cannot be rejected by virtue of an objective chi‐squared

ISSN:0002-8231    

DOI:10.1002/asi.4630360506

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThis paper introduces two data distortion methods: Frequency‐Imposed Distortion and Frequency‐Imposed Probability Distortion. This paper compares the performance of these distortion methods with that of other distortion method by using a Monte Carlo study. The study indicates that the data generated by these two methods not only produce accurate statistics but also protect the privacy of individuals involved in the d

ISSN:0002-8231    

DOI:10.1002/asi.4630360507

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractDatabase management systems are in widespread use as efficient means for managing information in a computer. This paper describes how the use of such systems is being taught to students at the School of Library and Information Studies, University of California, Berkeley. It discusses some of the concepts of database systems and presents an instructional data base used by students in the course.

ISSN:0002-8231    

DOI:10.1002/asi.4630360508

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

ISSN:0002-8231    

DOI:10.1002/asi.4630360509

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractA new model of viewing a document based on the citingcited relationship between documents is introduced. Using Bayes' decision theory, it is shown how a source document may be indexed and weighted by its set of relevant cited or citing document features, corresponding to a one pass relevance feedback Model 1 (probabilistic indexing) or Model 2 (probabilistic retrieval) system of [8]. Once every document in a collection has been so indexed, various forms of similarity measures based on probability of topical relevance between documents are derivable, including asymmetric, symmetric, and the relationship with Model 3 of [8]. Applications to retrieval and document clustering are also discussed.

ISSN:0002-8231    

DOI:10.1002/asi.4630360510

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

ISSN:0002-8231    

DOI:10.1002/asi.4630360511

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY