Science and technology constitute a primary productive force. As an important evaluation tool for Scientific and technological achievements and scientific and technological talent, SCI is well-known in the academia. As an authoritative scientific citation analysis tool and unique literature search tool enable China embrace the world and the world appreciate China, SCI was widely used in the activities of scientific research and technology management. To make the research staffs to learn more about SCI, we presented the knowledge and concept about citation analysis to the teachers and students, offer reference only.
In 1963, Eugene Garfield’s Institute for Scientific Information (ISI) started the Science Citation Index (SCI). The Science Citation Index (SCI) is an international, multidisciplinary and comprehensive citation index, involving several disciplines, such as science, technology, agriculture, forestry, medicine, biology, life science, astronomy, geography, environment, materials, engineering, natural and other disciplines. From the number of source journals SCI can be divided into SCI and SCI-E. SCI covers about 3600 journals and there are CD and printed editions. The larger version SCI-E (Science Citation Index Expanded), also called SCI Search, covers 5600 of the world’s leading journals of science and technology. It is made available online through the Web of Science database, a part of the Web of Knowledge collection of databases. SCI has 3 forms of printed edition as bi-monthly, annual and multi-year accumulation, the contents include five parts: Citation Index, Patent Citation Index, source Index, institutions index and permuterm index. SCI is not only a large-scale document retrieval tool, but an extremely important citation analysis tool.
B. Chinese Science Citation Database
Chinese Science Citation Database (CSCD) is a large-scale multi-functional database developed by CAS Documentation and Information Center, and funded by National Natural Science Foundation of China and Chinese Academy of Sciences. CSCD published a collection of 582 kinds of technical core journals in English and Chinese, covering mathematics, physics, mechanics, chemistry, astronomy, earth science, biological sciences, agriculture sciences, medicine and health, health, engineering, environmental science, and other fields.
CSCD was founded in 1989 and now has accumulated a sources database of 500 000 and 300 000 citation data. The information of paper citations (journal articles, monographs, conference papers, dissertations, and patent documents), journal citations, the papers published in core journals by organizations or individuals can be retrieved in this database, and it is the only integration of SCI in China.
C. Scientific Indicators
Scientific indicator is a measure of quantitative requirement project of the scientific strength. Currently, though the statistical indicators related to science are different in different countries, usually the scientific indicators include: number and types of scientific publications, number of citations of publications, number of personnel at all levels of degrees conferred, the amount of science foundation and strength of government, number of patents applied and approved, and the number of scientists employed. These indicators are often used to evaluate the scientific results and scientific production capacity.
Bibliometrics is a branch of science of library and information science, it use the number of features of various documents, to describe the mathematical and statistical methods, evaluate and predict the status of science and technology and development trend. In 1969, this term was first proposed by the British A. Pritchard
It is a set of methods used to study or measure texts and information. Citation analysis and content analysis are commonly used bibliometric methods. While bibliometric methods are most often used in the field of library and information science, bibliometrics have wide applications in other areas. In fact, many research fields use bibliometric methods to explore the impact of their field, the impact of a set of researchers, or the impact of a particular paper. Bibliometrics are now used in quantitative research assessment exercises of academic output which is starting to threaten practice based research.
E. The core institution of sci-tech papers
Pointers of the core area’s distribution of Sci-tech Papers’ capability and influence have transplanted the cumulative percentage method of core journals in statistical method.
The phenomenon of high-yield sectors’ high degree of concentration is a marked character of science and technology activities in the contemporary era. With the number and citations of papers as two basic data, and the cumulative percentage method, we can derive high-yield group and high academic groups.
Take the core area of science and technology statistical papers for example. The papers, firstly being collocated in descending order, then calculated the percentage of each sector’s thesis number and the total papers. We cumulate percentage from the up bottom, when the ratio was cumulated to 70%, the data will show the fact that a small number of institution have published the majority of papers. This small number of institutions has formed the core of Tech Papers Region.
Bradford’s law is a pattern first described by Samuel C. Bradford in 1934 that estimates the exponentially diminishing returns of extending a search for references in science journals. One formulation is that if journals in a field are sorted by number of articles into three groups, each with about one-third of all articles, then the number of journals in each group will be proportional to 1:n:n². There are a number of related formulations of the principle.
G. Literature Obsolescence
Scientific and technical literature, with the growth its “Age,” the contents become increasingly obsolete, and lost its value as a source of scientific information, therefore it became less and less useful for scientific workers and experts. The aging of scientific literature is both a significant social phenomenon and a complex dynamic process.
Half-life is commonly understood as meaning the time during which one-half of the currently active literature was published. Half-life of literature is not for a literature or a group of individual documents, but for the sum of the literatures in a particular discipline or professional field.
Broadly, a citation is a reference to a published or unpublished source (not always the original source). More precisely, a citation is an abbreviated alphanumeric expression (e.g., [Newell84]) embedded in the body of an intellectual work that denotes an entry in the bibliographic references section of the work for the purpose of acknowledging the relevance of the works of others to the topic of discussion at the spot where the citation appears. Generally the combination of both the in-body citation and the bibliographic entry constitutes what is commonly thought of as a citation (whereas, bibliographic entries by themselves are not).
J. Citation Analysis
Citation analysis is the examination of the frequency, patterns and graphs of citations in articles and books. It uses citations in scholarly works to establish links to other works or other researchers. It is one of the most widely used methods of bibliometrics.
A self-citation is a reference an author provide in a document to other documents written by the author. There are self-citation of papers, journals, and institutions.
L. Core journal
There is a universal phenomenon for the papers published, that is a minority of journals publishes most of the papers in a given discipline or professional, and it is the phenomena of the “few generating the many” and result in “core journal.”
1. Citation: Citation is commonly used in evaluating core journals. It range journals in an order of frequency of the published paper being cited, and the one with a large number of citation is considered a core academic journals.
2. Abstract: Abstract is also commonly used Method in evaluating core journals. It ranged journals in a directory in order according to the frequency of extractions of the secondary literature, and as journals and selected based on importance, and it is the basis for the importance and the selection of journals. Those journals with higher extraction and citation number can be selected as the core journals
3. Cumulative Percentage: cumulative percentage is commonly used for determining whether it’s a core journal or not. When it’s used in actual practice, you will put the amount of related journal papers by number in descending order, and in turn cumulate the journals published articles of top n,then calculated the percentage of cumulated published articles and statistical total ones of the journal. If the percentage number meets the selected requirement, then the pre-n journals are recognized as core journals. Otherwise, you need to calculate the following journals until it reaches the selected ratio. As the general requirements for the ratio is 80%, therefore the Cumulative Percentage may also be called way of 80%
4. Flow rate: Flow rate is one of the means to evealuate the core journals. The basic idea is: Through the analysis of the flow rate to the collection of periodicals within a certain time, take the times of lending, being reviewed in library, being copied and the loan frequency into consideration, the journals with higher circulation rate is the core ones
5. Comprehensive Evaluation: the number of Journals being cited, extracted, and circulated has shown the utilization conditions, which can be used to decide the importance of journals and as a reference for determining whether it’s the core journals or not, while in actual use, they may have their own weaknesses. The so-called comprehensive assessment is to improve the accuracy and effectiveness of core journals, and use the intersection of three combined methods, among which are method of citation, digest as well as the flow rate.
Citation quantity usually refers to the number of references of the cited reference; it is an important parameter to study the extent and breadth of the research literature being used.
N. Immediacy Index
An immediacy index is a measure of how topical and urgent work published in a scientific journal is. The immediacy index is calculated based on the papers published in a journal in a single calendar year. For example, the 2005 immediacy index for a journal would be calculated as follows:
A = the number of times articles published in 2005 were cited in indexed journals during 2005
B = the number of articles, reviews, proceedings or notes published in 2005
2005 immediacy index = A/B
O. Impact Factor
The impact factor, often abbreviated IF, is a measure reflecting the average number of citations to articles published in science and social science journals. The impact factor of a journal is the average number of citations to those papers that were published during the two preceding years.
P. Source journals
Source journals are a group of representative journals selected from a large number of publications, based on the research needs and the determined range of subjects. They can fully reflect the development of disciplines and provide appropriate sources of data for research and analysis.