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More and more frequently researchers are required to show both the academic and social impact of their work. When submitting grant proposals and during performance reviews impact has become a standard required talking point.

Showing academic impact seems easy as it is more easily quantifiable. When a researcher publishes an article that receives a large number of citations, the primary argument for academic impact has already been made.

Social impact is harder to prove, because what are you quantifying? Obtaining a patent, developing new teaching methods, or discovering a new medicine are concrete, quantifiable examples of social impact, but in most cases results will not be this tangible.

Leiden University offers assistance in this process through the Impact Matrix as part of the Protocol for Research Assessment. http://research.leiden.edu/research-output-assessment/research-assessment/leiden-university-protocol-for-research.html

Bibliometrics and Altmetrics are practical methods to draw a picture of your impact through quantitative means.


Since their conception in the Sixties, partly thanks to Eugene Garfield’s Science Citation Index, bibliometrics have been generally accepted. They are based on citation analysis and are mainly focused on journal articles. The most well-known bibliometrics are the Journal Impact Factor (JIF) and the h-Index.

What exactly do bibliometric scores signify? Some scores say something about the reputation of a specific journal, others say something about the use of the article in further research, and yet others say something about the productivity and impact of a researcher.

Most of these metrics have disadvantages: the JIF is an indication of journal impact rather than an individual researcher’s impact and the h-Index disadvantages early career researchers. However, all forms of judging impact based on citation analysis share the problem that it can take a long time for citations to accrue. Depending on the research field it can take up to two years for citations to appear.

Additionally, journal articles are not the primary publication form for every field. This has led to the development of altmetrics in the past few years. For more information on bibliometric indicators, see: http://guides.library.illinois.edu/impact/bibliometrics


The internet and social media have profoundly changed the world of scholarly publishing and science communication.

The increasing digitisation of the scholarly publication model has allowed for the possibility to start collecting data about an article’s reach. Originally altmetrics were developed at an article-level, but more and more publication forms (such as books and data sets) are being included all the time. They mainly take online interactions into account, such as views and downloads, but also social media mentions such as tweets, likes, etc.

It is important to realise that altmetrics scores measure the attention a publication gets, they do not say anything about the quality of a paper. They do give an indication of the visibility of the research and the researcher and whether the research results are being applied.

Additionally, they can provide insight into which audiences are being reached: peers, interested laymen, or the press. Arguably altmetrics reveal more about social impact than academic impact, though research has shown that there is a small correlation between social media mentions and old-school citations.

For more information on altmetrics: http://connectedleidenresearcher.nl/in-depth/what-are-altmetrics