The "impact factor" is a measure developed from data collected from the Web of Science. It is often used as a measure of the importance or impact of a journal's articles on known knowledge.
"The impact factor reflects the number of citations of a journal’s material in the preceding two-year period divided by the number of citable materials (source items) published by that same journal within the same period." (Kurmis, 2003)
The impact factor has received some criticism that the scholarly community has overestimated its importance and is being misused. Other citation metrics have also been developed, including the H-index, the Eigenfactor, and SCImago Journal Rank.
is a collection of databases including
Science Citation Index Expanded, Social Sciences Citation Index, and Arts & Humanities Citation Index are collectively known as the Web of Science (WOS).
What makes Web of Science unique is that it was the first database to include a search feature using the references of a journal article. Because a good paper provides references related to its own topic in its references, those references can be mined for other relevant publications on your topic. And, if you can also search for the papers that cited this paper in their own references, you can assume that those new papers were published on a related topic and they also may be relevant to your topic. Web of Science is designed to take advantage of these relationships to help you find relevant documents, as well as being searchable in traditional ways.
The founder of Web of Science and the originator of the concept of citation searching by database was Eugene Garfield, a chemist. He based his concept on "shepardizing." In law, many decisions about a case are based upon precedent. Shepardizing is the tracking of "publications which have referred to the case, the other court decisions which have affected the case and any other references which may be of value to the lawyer." (Garfield, 1994) Garfield thought this might be useful to the study of science literature.
Eugene Garfield designed Web of Science starting with journal articles in the science disciplines. The sciences publish primarily in journals and have strict criteria regarding the correct application of the scientific method. Therefore, Garfield set very strict criteria for the journal titles that were included. For this reason, Web of Science is most useful to the sciences; less useful to the social sciences; and only moderately useful to the humanities.
One reason for this is that the humanities publish their research as often in books as in journals--WOS only indexes journals. A second reason is that social science and humanities journals have less frequently met the strict criteria that WOS requires for its journal content. The social sciences are less able to apply rigorous scientific methodology to their research for ethical or logistical reasons. For example, you can't not educate a group of children to create a control group for your research. Or you can't manipulate a real business to find out what management methods work best--the company would never allow it. WOS has realized this and is relaxing its standards for social science and humanities journals.
Part of ISI Web of Science, the Science Citation Index Expanded is a multidisciplinary index to the journal literature of the sciences. It fully indexes 5,900 major journals across 150 scientific disciplines. The Science Citation Index Expanded includes all cited references captured from indexed articles. This database also provides a unique searching method, cited reference searching. With this resource, users can navigate backward in time using cited references to uncover the research that influenced an author's work or navigate forward in time using Times Cited to discover the impact a paper or other published item has had on current research. Science Citation Index Expanded averages 19,000 new records per week and includes approximately 423,000 new cited references per week. Some of the disciplines covered include: Agriculture, Neuroscience, Astronomy, Oncology, Biochemistry, Pediatrics, Biology, Pharmacology, Biotechnology, Physics, Chemistry, Plant Sciences, Computer Science, Psychiatry, Materials Science, Surgery, Mathematics, Veterinary Science, Medicine and Zoology. Coverage is from 1984 to the present.
Part of ISI Web of Science, the Social Sciences Citation Index is a multidisciplinary index to the journal literature of the social sciences. It fully indexes more than 1,725 journals across 50 social sciences disciplines, and it indexes individually selected, relevant items from over 3,300 of the world's leading scientific and technical journals. This database also provides a unique searching method, cited reference searching. With this resource, users can navigate backward in time using cited references to uncover the research that influenced an author's work or navigate forward in time using Times Cited to discover the impact a paper or other published item has had on current research. Social Sciences Citation Index averages 2,900 new records per week and includes approximately 60,000 new cited references per week. Some of the disciplines covered include: Anthropology, Political Science, History, Public Health, Industrial Relations, Social Issues, Information Science & Library Science, Social Work, Law, Sociology, Linguistics, Substance Abuse, Philosophy, Urban Studies, Psychology, Women's Studies and Psychiatry. Coverage is from 1984 to the present.
Arts & Humanities Citation Index®, accessed via Web of Science, provides researchers, administrators, faculty, and students with quick, powerful access to the bibliographic and citation information they need to find research data, analyze trends, journals, and researchers, and share their findings. Overcome information overload and focus on essential data from over 1,395 of the world's leading arts and humanities journals, as well as selected items from over 6,000 scientific and social sciences journals, with coverage available to 1975.
