How does a researcher gauge the impact of his/her research? How do administrators objectively evaluate the performance of a researcher? While both questions are difficult to answer, below are numeric measures that can provide a rough snapshot of impact. On this page:

Citation Count

The number of citations to articles and books they’ve written provides a measurable indicator of an individual’s impact, providing a crude measure of how much their work is being used to advance the research of others. This raw count of citations will vary depending on what the data source includes, and it’s hard to compare for researchers in different fields and at different career stages. Citation counts can be found in:

Article Download Count

Some web platforms provide download counts for individual hosted publications. This activity measure indicates interest at that level, but because of non-uniform criteria, there is no standard way to aggregate counts from different systems. Examples of platforms that provide download counts include the University’s Digital Conservancy (via an item's Stats Display), and Public Library of Science (in an article's Metrics tab).


This measure aims to capture productivity as well as impact by counting how many of an author’s papers have been cited many times; to have an h-index of 5, five of a scholar’s publications must have been cited by others at least five times each. While more sophisticated than plain citation counts, the h-index shares the limitations of incomparability across fields and across career stages. An individual’s h-index may be found in


Further Reading

Science Metrics, a Nature News special issue (6/16/10) discussing various individual productivity measures. Back to Research Impact Measures Home

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