Below are presented four examples of important data sources used for bibliometric studies.
The first two are used for citation analyses of a given number of articles or to estimate the number of articles a unit has published in international refereed journals. The last database type is an example of a data source that can form a basis for a type of evaluating bibliometrics that takes into account other publishing channels than solely journals.
Besides bibliographic data that is normally used to identify a document, such as author, title, journal, and publication date, citation databases also index the reference lists of all journal articles included in the database. Originally intended to complement the traditional methods for information retrieval, citation databases are nowadays also used to count the number of citations a given publication has received.
Web of Science, owned by Thomson Reuters, has been the leading source of evaluating bibliometrics as it has a multi-disciplinary and international coverage of refereed journals. An alternative to Web of Science was introduced in 2004, with the launch of the database Scopus. These two databases index a great number of journals within most disciplines, but the coverage varies, as indicated below, both concerning active journals and how far back in time the reference lists in articles in these journals are indexed. Accordingly, studies of the same analyzed units may yield different results, depending on which database is used.
Google Scholar is, in contrast to Web of Science and Scopus, a license free service. But due to the information about coverage, quality of indexed data, and difficulties in performing subject field normalization, it is not regarded as an alternative to the commercial citation databases as a source for evaluating studies.
Gives access to three citation indexes:Science Citation Index Expanded (coverage 1945-). Social Sciences Citation Index (coverage 1956-). Arts & Humanities Citation Index (coverage 1975-).
All in all, they cover approximately 10,000 refereed journals.
Indexes more than 15,000 refereed journals. But only from 1996 are the reference lists indexed consistently.
Google Scholar indexes a vide variety of scientific literature available on the Web: journals, books, preprints, reports and material from digital archives. The coverage from before 1996 is weak.
Local or national repositories are built on self-registering of publications. Today, most universities have publication databases presenting researchers' publications. This type of database may form the basis for an analysis of publication patterns and evaluation (see further Evaluative bibliometrics).
Content updated 2017-12-15