Citation counts measure the impact of a particular publicaton or an individual author by counting the number of times either has been cited in other works. This analysis of a particular author's work is one of the components used to evaluate the quality of that's individual's scholarly output and the impact he or she is having upon a particular discipline. Although such counting sounds relatively straightforward, it is complicated by the fact that there is no single citation analysis source that covers all publications and their cited references.
There are a number of ways to measure this:
Citation analysis as a qualitative measurement should be used cautiously, for the following reasons:
The two primary sources for citation information are:
When looking for citation counts, is it better to use Web of Science or Google Scholar?
SInce each has its advantages and disadvantages, it's really a good idea to search both and compare the results. And you may also want to consult discipline-specific databases that offer citation data.
Anne-Wil Harzig, Professor of International Management at the University of Melbourne and creator of Publish or Perish software, offers a good analysis of the relative disadvantages of both Web of Science and Google Scholar in her article, Google Scholar: A New Data Source for Citation Analysis.