Authors often track the sources that cite their work to see the impact of their research. Researchers also look for citing articles to trace the evolution of research and ideas. Just as examining an article's bibliography allows you to look backward at its influences, examining the sources that subsequently cite an article reveal its influence in its subject.
There are a number of sources available to researchers to discover citations, including Google Scholar and Web of Science.
Note: Citations are the traditional "article-level metric"--that is, a measure of the influence of published research at the article level. Most Altmetrics are also tracked at the article level; however, Altmetrics and article-level metrics are not quite synonymous.
What are the caveats and limitations?
- Subjects vary significantly in their citation patterns (because of their size, because of the types of sources researchers use, and because of the number of sources articles cite on average). Just as it is inappropriate to compare impact factors among fields, it is inappropriate to discuss citation counts without reference to the field of study. "Highly cited" might mean a very different number of citations in two different fields. It is entirely normal, for example, for publications in the humanities to have lower citation counts than articles in the physical sciences.
- Consider the age of articles when searching for citations. In many fields, articles continue to accumulate citations for years (or occasionally even decades) after they are published. Likewise, very recent articles usually cannot be expected to have received any citations yet, regardless of their quality.
- Multiple databases track citations. None of them are guaranteed to find all citing articles, and they often duplicate one another. Users should not simply examine citation counts and add them up. Rather, lists of citing articles should be examined and duplicates removed before citation counts are reported.
- Suppose different databases find the following for a selected article:
- Google Scholar: 15 citations
- Web of Science: 8 citations
- PsycINFO: 12 citations
- Total ≠ 35!
- The total number of citations is not 35: it's 35 minus the duplicates that appear in multiple databases.
