Citation analysis, the statistical analyses of citation counts, have found widespread application in the research community in the area of research evaluation. They are being used to infer quality or academic impact at the level of an individual article, a journal, an individual researcher, as well as aggregated to infer quality at the research group, discipline, and organizational unit within an institution, institution and country level.
For an individual article, the number of times it has been cited by other articles is generally considered to be indicative of the article’s academic impact, with the assumption being that research articles of high academic quality are likely to be cited more often than those of lesser quality. Other metrics, including secondary citations (the number of citations received by the articles citing the article) have also emerged.
For an individual researcher, the following are the most common citation metrics in use:
Career citation count
Career citation count with self-citations removed
Citations per paper
h-index (Hirsch index)
For selected articles: total citations, citations per paper etc
To profile a research group, the measures which are typically used include the total number of publications in a given timeframe (e.g. last 5 years) , the total citation counts (for the publications within the timeframe), and the ratio of these two, the citations per paper. Recently, the h-index has also been applied to entities such as research groups, although the index was developed and introduced as an indicator for an individual researcher.
To profile a large group of researchers across many disciplines, a more detailed analysis of their research outputs would consider the measures mentioned above (total number of publications in a given timeframe, the total citation counts (for the publications within the timeframe), and the ratio of these two, the citations per paper) disaggregated at the discipline level.
Other citation metrics consider the analysis of the citations by journal, country or institution etc.