To date, a range of metrics is available to assess the contribution of research and researchers to the evidence-based knowledge and progress in academia.
To appreciate the merits of specific measures of impact, it is important to understand that some well-known metrics, like the impact factor, reflect on the significance or quality of scholarly journals as a whole. Others are indicative of the impact of a specific academic article, which inherently reflects on the success and quality of individual researchers.
Another essential detail, which defines a measure of impact in academic research, is the data source used to calculate the metric outcome for a journal or article. The most comprehensive internationally recognised citation data sources for research impact metrics are the Web of Science, Scopus and Google Scholar. Research staff and students at Notre Dame have access to these data sources via the Library.
Quantitative analysis of research output by journals and researchers is referred to as bibliometrics. An introduction to why bibliometrics and measures of impact matter in academia is provided by the Library at Notre Dame.
The University administers an electronic repository of scholarly publications authored by its staff and students. ResearchOnline@ND brings all research published by Notre Dame researchers together in one database, ideal for bibliometric assessment of one's track record in research.
Over view of internationally used key metrics
|Web of Science||Scopus||Google Scholar|
|5-yr Impact Factor|
|Eigenfactor||Scimago Journal Rank|
|Source Normalized Impact (SNIP)|
|Article Influence Score|
|Google Scholar H-5 Index|
|Google Scholar Metric|
|Altmetric Attention Score|
The factsheet 'Mastering Metrics- A Taylor & Francis guide' provides further insight into each metric type and how it is calculated.
Journal metrics generally rely on the average article citation rate in a given year. It is important to note that a journal metric outcome reflects on the overall impact of the journal. The journal metric outcome should not be used as a quality indicator for individual articles published in the journal.
The best known Web of Science-based journal metric is the Impact Factor (IF), which considers all citations to articles published during a 2-year period prior to the IF year. Alternatively, a 5-yr IF considers all citations to articles published during a 5-year period prior to the IF year, while the Scopus-based CiteScore considers all citations to articles published during a 4-year period prior to the year of interest.
Other journal metrics have weighed in the prestige of the journal in which an article is cited (Eigenfactor; Scimago Journal Rank ), or the citation context by considering the subject field of the journal in which an article is cited ( Source Normalized Impact ).
An Immediacy Score presents the average article citation rate in the year of their publication, while an Article Influence Score reflects the average impact of a journal's collection of articles during the first 5 years after publication.
Journal Ranking scores are defined by journal metrics. Knowledge on journal ranking can be helpful in the selection of a journal to publish in, especially within specialist disciplines where a journal's ranking may be of more value than the IF.
The best known article metric is the H-index (Hirsch-index). It is a publication related metric, which reflects on the quality and impact of publications by an individual researcher. Data retrieval for the H-index calculation is not restricted to one particular data source, but its outcome may vary slightly depending on which online platform is used for its calculation. Similar article citation metrics can be generated in Google Scholar.
Published authors can stay on top of their citation track record by setting up automated Citation Alerts in the 3 main data bases: Web of Science, Scopus and Google Scholar.
It is more often recognised nowadays that research can have impact beyond the scholarly research community. The internet has opened the door to new types of communication about research and wider publicising of new research findings (often by others, like journalists) in print and online (social) media.
This new form of talk about research by the wider public can be tracked as impact with newly available metrics, the Altmetric Attention Score among others.
You can learn more on alternative measures of research impact through the Library.