Bibliometrics - learn more

Bibliometrics support researchers and research institutions by measuring the influence of articles in their discipline. Productivity, visibility and impact of research can be evaluated and collaborations and research trends identified.

The main advantages of bibliometrics are:

  • Quantitative measure of research impact, avoiding thus biased interpretation.
  • The analyses are transparent and the results can be reproduced by anyone.
  • Analyses can be performed for a person, group or institution on a national or international level.

Good practices

Based on the DORA Declaration and the Leiden Manifesto, principles for measuring research and its quality apply. We take this into consideration and make our analysis transparent by providing you the methods used for the analyses if requested. We follow these guidelines:

  • Indicators should be scaled and chosen carefully (e.g. indicators on a journal's level should not be used for individual articles).
  • Quantitative data are abstract concepts, and there is no simple way to measure the quality of research. Thus, bibliometrics can only be an indicator of quality; it should not be used for qualitative interpretation. Conclusions should be based on more than one indicator.
  • Research is measured differently across distinctive disciplines. For different disciplines, different indicators are of importance.
  • Metrics on individual researchers should not be used to compare with other researchers. For example, the h-index depends on a person's age and on the discipline and is not well suited for comparison among researchers.
  • All indicators should be transparent and easily understandable.
  • Data sources should be accurate.
good-practices

Metrics used in bibliometrics

There are numerous metrics used in bibliometrics and we list only a few below. Please note that such indicators should not be used as standalone figures, since they may depend on their context.

IndicatorExplanation
ProductivityAmount of publications within a certain time frame
CitationsAmount of citations the publications received
PPtop10%Proportion of an entity's publications that rank among the top 10% most-cited publications. This is normalized by field, publication year and document type. The world average is 10%. PPtop10% is robust against outliers. 
MNCS (Mean Normalized Citation Score)Average of each paper's citation count (for a given entity) divided by the world-average citation count for papers of the same field, publication year and document type. A value of 1 equals the world average and 1.5 means 50% above it. The MNCS is affected by outliers. Same or similar metrics are called FWCI or CNCI.
Journal Impact FactorIndicator for amount of citations of a journal. Shows how often an average article is cited after publication.
Please note that the JIF should not be counted as a qualitative indicator for any author's work. It measures citations on a journal's level and cannot be seen as indicator for an individual article.
h-indexDepicts the impact of an author's output.
AltmetricsShows the outreach of an article in social media. E.g. measured are downloads, views, bookmarks on Mendeley or also the amount of tweets.
metrics

Further reading

further-reading