INTRODUCTION
The term bibliometrics is derived from “biblion” (Gr.): book and “metron” (Gr.): measure; and introduced by Pritchard in 1969. Pritchard’s article “Statistical Biography or Bibliometrics?” appeared in the December issue of the Journal of Documentation in 1969. He stated, “The term (Statistical bibliography) is clumsy, not very descriptive, and can be confused with statistics itself or bibliographies on statistics”.
Bibliometrics is a set of methods used to study or measure texts and information. Citation analysis and content analysis are commonly used Bibliometrics methods. Bibliometrics methods are most often used in the field of library and information science.
In fact, bibliometrics method is used to explore the impact in the research. Bibliometrics also uses in quantitative research assessment.
Historically Bibliometrics methods have been used to trace relationships amongst academic journal citations. Citation analysis, which involves examining an item’s referring documents, is used in searching for materials and analyzing their merit. Citation indices allow users to search forward in time from a known article to more recent publications which cite the known item.
Definitions:
Alan Pritchard (1969), who first used the word “bibliometrics,” described it as the “application of mathematics and statistical methods to books and other media of communication”. Pritchard explained in his later articles, bibliometrics as the “metrology of the information transfer process and its purpose is analysis and control of the process”.
Fairthorne (1969) defined as “quantitative treatment of properties of recorded discourse and behavior appearing to it. Bibliometric is also explained as quantitative analysis of bibliographic features of body of literature.”
British Standard Institution (1976) described bibliometrics as “application of mathematical and statistical methods in the study of the use of documents and publication patterns.”
Hawkins (1977) defined bibliometrics as “the application of quantitative analysis in the bibliographic references of the body of literature.”
Nicholas and Ritche (1978) accepted the definition of bibliometrics as “the statistical or quantitative description of literature.”
Schrader (1981) defined as “the scientific study of recorded discourse.”
Potter (1981) meant that “the study and measurement of all forms of written communication, their authors and publication patterns.”
Egghe (1988) explained “the development and application of mathematical models and techniques to all aspects of communication. Bibliometrics is the quantitative study of literatures as they are reflected in bibliographies. It’s task, immodestly enough, is to provide evolutionary models of science, technology and scholarship.”
Diodato (1994) described as “the study of publications and communication patterns in the distribution of information by using mathematical and statistical techniques, from counting to calculus.”
Oxford English Dictionary defines Bibliometrics as “The branch of library science concerned with the application of mathematical and statistical analysis to bibliography; the statistical analysis of books, articles, or other publications”.
According to Lancaster Bibliometrics is “the discipline of measuring the performance of a researcher, a collection of articles, a journal, a research discipline or an institution”. This process involves the ‘application of statistical analyses to study patterns of authorship, publication, and literature use’.
Bibliometrics is nothing but counting of publications and citations i.e. measuring the output and the impact of scientific research. Bibliometrics means evaluating and ranking people and institutions, countries and research outputs.
Bibliometrics applied to scientific articles is called `Scientometrics’ Scientometric has been typically defined as the “quantitative study of science and technology”
Nalimov and Mulchenko (1969) of USSR defined scientometrics as “the quantitative methods which deals with the analysis of science viewed information process.”
Beck (1978) defined as “the quantitative evaluation and inter-comparison of scientific activity, productivity and progress.”
Brookestein (1995) defined scientometric as “the science of measuring science.”
Tague-Sutcliffe (1992) defined that “study of the quantitative aspects of science as a discipline or economic activity. It is part of the sociology of science and has application to science policy-making. It involves quantitative studies of scientific activities including, among others, publication, and so overlaps bibliometrics to some extent.”Hence it is concluded that scientometrics is bibliometric measurement for assessment of scientific development, community relevance and impact of application of science and technology.Informetrics is based on the combination of advances of information retrieval and quantitative studies of information flows.
Tague-Sutcliffe (1992) defined informetrics as “the study of the quantitative aspects of information in any form, not just records or bibliographies, and in any social group, not just scientists.”
Ravichandra Rao (1993) stated that “Informetrics connotes the use and development of a variety of measures to study and analyze several properties of information in general and documents in particular.”
Ingwersen & Christensen (1997) “the term informetrics designates a recent extension of the traditional bibliometrics analyses, also to cover non-scholarly communities in which information is produced, communicated, and used.”
Hood and Wilson (2001) stated that “informetrics covers the empirical studies of literature and documents, as well as theoretical studies of the mathematical properties of the laws and distributions that have been discovered.”
Bossy introduced the term Netometrics’ to describe internet-mediated scientific interaction. The study of the world wide web and all network-based communications, by informetrics method measured through webometrics or cybermetrics which is being suggested in 1997 by Almind and Ingwerson.
Bjorneborn and Ingwersen (2004) defined webometrics as “the study of the quantitative aspects of the construction and use of information resources, structures and technologies on the web drawing on bibliometric and informetric approaches.”
Thus bibliometrics, scientometrics, informetrics, webometrics or cybermetrics are studies to measure bibliograpbhic details in the form of typical bibliography, scientography, informagraphy, webography or cybergraphy respectively.
Laws of Bibliometrics:
One of the main areas in bibliometric research concerns the application of bibliometric laws. The three most commonly used laws in bibliometrics are – Lotka’s Law of Scientific Productivity, Bradford’s Law of Scatter, and Zipf s Law of Word Occurrence;
i. Lotka’s Law of Scientific Productivity:
In 1926, Alfred J. Lotka proposed an inverse square law relating to scientific papers to the number of contributions made by each author. Lotka’s Law describes the frequency of publication by authors in a given field. It states that “. . . the number (of authors) making n contributions is about 1/n2 of those making one; and the proportion of all contributors, that make a single contribution, is about 60 percent”. This means that out of all the authors in a given field, 60 percent will have just one publication, and 15 percent will have two publications (1/22 times . 60), 7 percent of authors will have three publications (1/32 times . 60), and so on. According to Lotka’s Law of scientific productivity, only six percent of the authors in a field will produce more than 10 articles. Lotka’s equation is
xn X y = Constant
Where Y= Frequency of authors making n contribution, the value of the constant is found to be 0.6079
ii. Bradford’s Law of Scatter:
Samuel Clement Bradford in 1934 points out 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 and zones containing the same number of articles as the nucleus when the number of periodicals in the nucleus and succeeding zones will be 1: n: n2.
Bradford’s Law states that journals in a single field can be divided into three parts, each containing the same number of articles:
• A core of journals on the subject, relatively few in number, that produces approximately one-third of all the articles;
• A second zone, containing the same number of articles as the first, but a greater number of journals, and
• A third zone, containing the same number of articles as the second, but a still greater number of journals.
The mathematical relationship of the number of journals in the core to the first zone is a constant n and to the second zone, the relationship is n2. Bradford expressed this relationship as 1: n: n2. Bradford formulated his law after studying a bibliography of geophysics, covering 326 journals in the field. He discovered that 9 journals contained 429 articles, 59 contained 499 articles, and 258 contained 404 articles. So it took 9 journals to contribute one-third of the articles, 5 times of 9, or 45, to produce the next third, and 5 times 5 times 9, or 225, to produce the last third.
Bradford’s Law serves as a general guideline to librarians in determining the number of core journals in any given field. Bradford’s Law is not statistically accurate, but it is still commonly used as a general rule of thumb.
iii. Zipf’s Law of Word Occurrence:
George K. Zipf, 1947 states that if the words occurring in a natural language text of sizable length are listed in the order of decreasing frequency then the rank of any given word in the list would be inversely proportional to the frequency of occurrence of the word.
Zipf’s equation is
r x f=k
Where r = Rank; f = Frequency of Word; k = Constant
The Law states that in a relatively lengthy text if you list the words occurring within that text in order of decreasing frequency, the rank of a word on that list multiplied by its frequency will equal a constant. The equation for this relationship is: r x f =k where r is the rank of the word, f is the frequency, and k is the constant. Zipf illustrated his law with an analysis of James Joyce’s Ulysses. He showed that the tenth most frequent word occurred 2,653 times, the hundredth most frequent word occurred 265 times, the two hundredth word occurred 133 times, and so on. Zipf found, then that the rank of the word multiplied by the frequency of the word equals a constant that is approximately 26,500″.
