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Bradford distributions describe the relationship between ‘journal productivities’ and ‘journal rankings by productivity’. However, different ranking conventions exist, implying some ambiguity as to what the Bradford distribution ‘is’. A need accordingly arises for a standard ranking convention to assist comparisons between empirical data, and also comparisons between empirical data and theoretical models. Five ranking conventions are described including the one used originally by Bradford, along with suggested distinctions between ‘Bradford data set’, ‘Bradford distribution’, ‘Bradford graph’, ‘Bradford log graph’, ‘Bradford model’ and ‘Bradford’s Law‘. Constructions such as the Lotka distribution, Groos droop (generalised to accommodate growth as well as fall‐off in the Bradford log graph), Brookes hooks, and the slope and intercept of the Bradford log graph are clarified on this basis. Concepts or procedures questioned include: (1) ‘core journal’, from the Bradfordian viewpoint; (2) the use of traditional statistical inferential procedures applied to Bradford data; and (3) R(n) as a maximum (rather than median or mean) value at tied‐rank values.

It is well known that the laws of Leimkuhler, Mandelbrot, Lotka and the verbal formulation of Bradford's law are equivalent. In this note we prove an analogous framework of laws in which now the law of Zipf occurs instead of Mandelbrot's law. Laws in this group are Brookes' law and the graphical formulation of Bradford's law. We show that both groups of laws are very different in the sense that they are not even equal asymptotically for high rankings.

The Bradford law is explored theoretically by means of a very mixed Poisson model which, it is claimed, elucidates the uncertainties surrounding the law and its applications. It is argued that Bradford succeeded in formulating an empirical regularity which has pure and hybrid forms but that all the variants can be subsumed under a simple logarithmic law which, for reasons explained, escapes exact expression in conventional frequency terms. The theoretical aspects discussed include the hybridity of form, estimations, sampling problems, the stability of ranks, homogeneity of data, and tests of significance. Some numerical examples, some simulated and some drawn from social contexts outside bibliography, are used both to illustrate theoretical issues and also to indicate the wide generality of the Bradford law. Possible applications and developments of the theory are indicated.

Word‐oriented databases of potential relevance to the multidisciplinary field of emergency management were identified by the University of Illinois, Information Retrieval Research Laboratory under contract to the United States Federal Emergency Management Agency (FEMA). This article is an extension and outgrowth of that contract. It analyzes forty databases for relevance to emergency management by searching each database using an emergency management subject profile, printing a random sample of citations to determine percent of false drops, and ranking the databases according to number of relevant citations. Bradford's law of scatter is shown to apply to this multidisciplinary field, using databases instead of journals and citations instead of articles. No one database provides more than 19% of the literature, however, illustrating that the literature in the field is widely scattered throughout databases. These findings can help in the choice of the specific databases containing emergency management citations and in the determination of how many databases need to be searched in order to retrieve a given percentage of the literature. A companion article in this issue of Online Review — ‘Evaluation of database coverage: a comparison of two methodologies,’ explains the subject profile evaluation method employed in this project and compares it to another coverage evaluation technique.

The present paper aims at analyzing the research output performance of library and information science (LIS) professionals. Citation analysis of all the journal articles published in the Collection Building journal during 2009-2012 is carried out.

The data for this study were drawn from a selective sample of a free e-journal, i.e. Collection Building, available through the Kuvempu University Web site without subscription or registration. A total of 91 articles published during 2009 to 2012 with 1,302 citations. The analysis cover mainly the number of articles, authorship pattern, subject-wise distribution of articles, average number of references per articles, forms of documents cited, rank list of journals, Bradford’s law.

The study reveals that journals (53.84 per cent of citations) are the most preferred sources of information used by the researchers in the field of LIS. It is followed by Web resources with 24.27 per cent, these two together constitute 78.11 per cent of total citations and remaining 21.89 per cent of citations from books, proceedings, theses, reports and gazetteer. Collection Building (USA) has ranked first with 68 (9.70 per cent) citations. Further, Bradford’s law of scattering was applied. It is observed that major citations are from journal literature. In addition, more cited materials were contributed by multi-authors, and degree of collaboration is 0.44.

The paper presents a sense of the importance of LIS research, and as such, informs the community and researchers involved in the citation analysis.

The outcome of the study is an original research work with citation analysis of LIS publications. The study highlights the information materials available and used by researchers in the field of LIS, and those that need to be added for a healthy collection.

Bradford's Law is presented as an observation made from the outcome of searching, rather than a mathematical development. The organization and presentation of search data is explained. Potential applications of Bradford's Law are discussed. New findings are presented which show the relationship described by Bradford's Law to be fundamentally important but in a more subtle way than previously supposed. Future developments are suggested in terms of their impact on librarianship.

This study aims to analyze the resources used in the citations of 156 postgraduate dissertations submitted to the Rajiv Gandhi University of Health Sciences (RGUHS) through the Acharya & BM Reddy College of Pharmacy (ABMRCP), and prepares the core journal list according to the Bradford’s law of scattering. For any research and academic institutional libraries, books and journals are considered as key resources. As the resources are more and diverse, collection building is a tough task for librarians. Citation analysis is one of the best methods to list the most used resources by the users. The paper highlights the extent use of in-house resources and open access journals in the citations.

Citations of PG dissertations during 2010-2013 (four years) were compiled, the data about the resources cited in each were taken and the list of resources used in PG dissertations was prepared. The list of core journals obtained by citation analysis was matched with the list of online journals provided by Health Science Library & Information Network (HELINET) of RGUHS as well as print list of journals subscribed by ABMRCP Library, and evaluated the print and online consortia journals used by ABMRCP community. The list of core journals’ ranking in the SCImago Journal & Country Rank (SJR) list-pharmaceutical sciences was identified to know the impact of the journals.

The study gives the list of different information resources cited in the pharmacy dissertations. The core list obtained by applying the Bradford’s law of scattering in this study has 19 journals pertaining to pharmacy. After matching the core list with the Keogh’s list, it is found that 31 journals can be considered very useful in the field of pharmacy. Twelve journals listed in the core list have different positions in the SJR ranking 2013. The results indicate that open-access journals with online journals subscribed through HELINET and print holdings have been cited more in the PG dissertations.

The topic of journal use in this case may be of greatest interest to those who purchase journals in the sciences and, very specifically, the pharmaceutical sciences.

An exact, discrete formulation of Bradford's law describing the distribution of articles in journals is derived by showing that Bradford's law is a special case of the Zipf‐Mandelbrot ‘rank frequency’ law. A relatively simple method is presented for fitting the model to empirical data and estimating the number of journals and articles in a subject collection. This method is demonstrated with an example application.

The purpose of this research is to examine the practical potentials of Bradford's law in relation to core‐journal identification.

Literature studies and empirical tests (Bradford analyses).

Literature studies reveal that the concept of “subject” has never been explicitly addressed in relation to Bradford's law. The results of two empirical tests (Bradford analyses) demonstrate that different operationalizations of the concept of “subject” produce quite different lists of core‐journals. Further, an empirical test reveals that Bradford analyses function discriminatorily against minority views.

Bradford analysis can no longer be regarded as an objective and neutral method. The received view on Bradford's law needs to be revised.

The paper questions one of the old dogmas of the field.

Several power law relations are found to occur in bibliographic studies of scientific journals, articles, and citations. These can be interpreted in a self‐consistent manner in terms of growth parameters of articles, journals, and citations. Similar models have been proposed earlier in physical, biological, and behavioural sciences.