Bibliometric analyses and quality indicators
Whereas peer review is a qualitative measure of the quality of an article, there are also quantitative measures of the quality (or, at least, the influence) of a scholarly article.
These measurements are bibliometric calculations based on citation analysis and are carried out within a particular data set. This can be a database (large databases such as Scopus and ISI Web of Science offer such analysis) or a set like Google Scholar.
A worldwide big player in the field of bibliometric analyses is the Centre for Science and Technology Studies, which is connected to the University of Leiden.