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Research Metrics@HKUL: Home



Research impact measurement is a controversial topic as there are no agreed standards. The most common measurement tools are research metrics, which are statistical analysis on the impact of published academic research, aiming to provide quantitative indicators for measuring and monitoring impacts of research output. They are widely applied in academia but often inappropriately. However, if research metrics are used appropriately, they can be very useful for research assessment.



The below listed a few common purposes that research metrics are being used for:

  1. Locating the most important research being done in a specific field

  2. Identifying the top journals in a field for publications

  3. Identifying an author’s research impact in the respective field(s), frequently driven by promotion and tenure

  4. Evaluating and benchmarking research outputs to support decision-making by the University administration

Research Metrics

Research Metrics

There are two main types of Research Metrics:


Citation Metrics (Bibliometrics)

Bibliometrics measure the attention level by analyzing the number of times that a piece of publication was cited by other researchers, reflecting impacts among the academic community. The analysis can be conducted at article, author, journal, or institutional level.


Alternative Metrics (Altmetrics)

Altmetrics aggregate the attention level that a piece of publication received in areas other than the scholarly publishing community, such as social media including Twitter, Facebook, blog posts, and and other platforms. It counts the number of times a piece of publication has been viewed, downloaded, exported to a citation manager, mentioned and shared on social media sites or media. It is often used to indicate the immediate impact of a piece of work and serve as a reference for possible intentions of citations.

In this guide, a range of key metrics and key analysis tools widely used for citation metrics will be introduced in detail. Metric tools are provided mainly by three sources, Clarivate, Elsevier and Google Scholar. It is important to note that in these tools, the publications included in their analysis are mainly, but not limited to, journal articles.


Responsible Use of Metrics

Responsible Use of Metrics

Although research metrics provide us a systematic method to measure research impact quantitatively, we have to be very cautious on the idea of citation being a fundamental indicator of research impact, as it is not synonymous with “quality”.

It is essential to bear in mind that one single metric, or a few measures only indicates a certain aspect of research performance, where it should not be representing the overall impact of a researcher or research output. Multiple factors, including other qualitative analysis measures, should be considered in assessing research quality. However, metrics could still be of value to multiple parties for particular purposes.

In addition, citation behaviour and average citations per article differ considerably among disciplines, and hence it is generally not useful to compare citation metrics across disciplines. For instance, papers in Medicine receive a high number of citations, while those in Social Science, Mathematics, or the Humanities may not be that high.

Head of Scholarly Communication and Research Services & Medical Librarian

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Jesse Xiao
5/F Main Library, The University of Hong Kong
(852) 2241 5841
Subjects: Medicine

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