Jan. 1, 2008 – The University Libraries subscribe to two databases offered by Thomson Reuters (formerly produced by ISI, the Institute for Scientific Information) that can play an important role in assessing the scientific and scholarly influence of article authors and of specific journals. With proper searching and informed interpretation of results, each of these products provides data which can contribute to responsible and appropriate evaluation in the promotion and tenure process.

The Web of Science allows users to search for all articles, within the thousands of journals covered in the database, that have cited a source article. By using the cited reference search feature and entering an author's last name and initials, one can find out how many times an author's works have been cited. This capability has been enhanced by the purchase of an extended backset, allowing the collation of all citations from covered publications dated 1975 to the most recent issues.

The value of citation counts is a matter of controversy. Even after self-citations have been eliminated (instructions for eliminating self-citations PDF), persons or committees responsible for evaluation must decide how much importance to place on this measure. It is important to bear in mind that the depth to which Web of Science covers academic disciplines varies greatly. Coverage is extensive in the sciences, and especially in the biomedical fields. Engineering and the social sciences are covered less comprehensively, and coverage in the humanities is highly selective. Another important factor is that the typical lag time between source document and subsequent citation may vary by discipline. Even within a given discipline, different types of articles also have different citation patterns.

The Journal Citation Reports (JCR) can provide interesting and informative measures that complement citation counts compiled for individual publications or authors. Here the unit of analysis is a journal itself, and among the many attributes that can be identified through the JCR the most frequently discussed is the "impact factor" associated with each journal. By indicating the frequency with which the typical article in a particular journal is cited in subsequent years, impact factors provide one measure of the influence and reputation of the journal that has accepted an author's contribution. High impact factors generally correlate with low acceptance rates, and the highest impact factors are usually found in widely recognized journals such as the New England Journal of Medicine, Nature, and Science.

As with individual citation counts, valid comparisons of impact factors require caution and a careful recognition of differences among disciplines. Eugene Garfield, the founder of ISI, discusses the impact factor and the reasons "it must be used discretely" in a 1994 essay we highly recommend to Virginia Tech faculty and administrators wanting to know more. A 2005 presentation by Garfield further details the history and meaning of the journal impact factor.

In addition, the Chronicle of Higher Education's Oct. 14, 2005 issue included an in-depth study of the rise of the impact factor's importance, in an article titled The Number That's Devouring Science.

This two page handouttwo page handout has some tips on cited reference searching in Web of Science.

For further information on these resources, please consult the Science Essays page or contact Ed Lener (231-9249) or your college librarian.