Citation analysis is a worthwhile area of research. "Citation analysis" refers to references in one text to another text, with information on where that text can be found. Citation analysis is useful for understanding subject relationships, author effectiveness, publication trends, and so on. The first recorded citation analysis was Gross and Gross (1927) who looked at citation patterns to determine the journals to be subscribed to and back volumes to be acquired for the library of Pomona College. They studied the citation frequency in the references given in the Journal of the American Chemical Society (Amudhavalli 1997). With citation analysis one can evaluate and interpret citations received by articles, authors, institutions, and other indications of scientific activity (Ravichandra Rao 1993).
Citation analysis is also a way to understand users. Studying references cited by your faculty's publications or your students' papers shows you the types of sources most commonly used and valued locally in their disciplines (Curtis 2005). It makes use of bibliographic references, which are an essential part of scientific communication (Encyclopedia of Library and Information Science, 1998). Citation analysis is a major area of bibliometric research, which uses various methods of citation analysis to establish relationships between authors or their work (Ane's Encyclopedic Dictionary of Library and Information Science, 2006).
Objectives of the Study
The study objectives are:
* To determine the principal forms of literature used in dissertations by LIS doctoral students
* To prepare a ranked list of periodicals based on frequency of use by doctoral students.
* To determine country-wise distribution of literature used by doctoral students.
* To determine the age distribution of literature used by doctoral students.
* To study authorship patterns in citations.
* To determine language-wise distribution of citations
* To determine subject-wise distribution of citations.
* To determine publisher-wise distribution of citations.
Twenty-seven LIS dissertations submitted to the University of Pune between 1982 and 2005 were selected a source of data. A total of 6,257 citations were found in all 27 dissertations. Data compiled includes year of publication of articles, and journal subject, language of journal, publication status, place of publication, and publisher of the journal taken from the online version of Ulrich's International Periodical Directory (http://www.ulrichsweb.com/). All references (bibliographies) were photocopied and each reference was categorized according to format or genre, i.e., book, journal, report, conference proceedings, newspaper, thesis/dissertation, and reference book. A list of periodicals was compiled and data was entered in SPSS.
PhD students prefer periodical literature as a source of information.
PhD students give less importance to non-periodical forms of literature.
PhD students prefer journals published in developed countries.
Distribution of Physical Forms of Publication
Table 1 summarizes the forms of publication cited.
Table 1 shows that 2,639 (42.2%) citations out of 6,257 were from journals, followed by books with 1,950 (31.2%).
Ranked List of Journals
Journals are essential for research but their increasing cost demands that librarians study their quality, usefulness, and suitability to a particular group of users. The ranking list is a practical tool to help select journals of maximum utility in relation to their coverage of new and important literature in a particular subject area. The ranked list of journals in the field of LIS is presented in Table No 2. Journals cited more than twice appear in the table. Titles are arranged in their decreasing order.
Table 2 reveals that the most cited journal by LIS researchers is College and Research Libraries, which was cited 141 times, more than 5.3% of the total percentage of citations, followed by Scientometrics, at 129 (4.9%), Journal of American Society for Information Science, 113(4.3%), Journal of Documentation, 99 (3.8%), Aslib Proceedings , 82 (3.1%), Library Quarterly, 78 (3.0%), and Library Trends with 62 (2.3%).
Bradford's Law of Scattering
Bradford in 1934 described a scattering pattern in applied geophysics. He plotted the partial sum of references against the natural logarithm of the partial sums of number of journals and noticed that the resulting graph was a straight line. On the basis of this observation, he suggested the following linear relation to describe a scattering phenomenon: F(x)=a+b log X, where F(x) is the cumulative number of references contained in the first X-most productive journals. "a" and "b" are constants, Bradford, thus, based on a semi-logarithmic group argued that:
If scientific journals are arranged in order of decreasing productivity of articles on a given subject, they may be divided into a nucleus of periodicals more particularly devoted to the subject and several groups or zones containing the same number of articles as the nucleus when zones will be 1:n:n2 ... where 1 represents the number of journals in the nucleus and 'n' is a multiplier. [GRAPHIC OMITTED]
In the present study, 11 journals covered 917 articles, the next 55 journals covered 914 articles, and the next 300 journals covered 770 articles. That is, 11 journals covered one-third of the total citations, the next 41 journals accounted for another one-third, and the final 300 covered the remaining third. Thus, the first zone or 'nucleus' contains 11 journals, followed by the second zone with 55, and the...