Citations and Research Impact
1. Measuring Research Impact
2. Research Impact of Researchers
3. Research Impact of Journals
1. Measuring Research Impact (top)
Publication and citation
counts are increasingly used to measure the impact of scholarly
research. Institutions and government agencies are using metrics related
to publication and citation numbers to evaluate and rank research
output and research impact of researchers, research institutes and even
of a country.
While it is good to have
some way to measure research performance and evaluate your research, it
is also important to note the following:
- Measuring research impact through citation counts is just ONE quantitative indicator
are other quantitative and qualitative approaches to measuring research
and they should be used collectively to obtain a holistic view of the
research and its impact. Citation counts and related citation metrics is
just ONE quantitative indicator of research performance.
- Citation patterns differ between subject disciplines
Citation metrics should not be compared across disciplines as citation patterns differ between subject disciplines.
- Citation databases are not complete
different citation databases cover different journals and in totality,
they do not cover the world’s entire scientific and scholarly output.
There are many publications not captured in these citation databases.
Hence, the results from the citation databases are not comprehensive and
should not be compared.
2. Research Impact of Researchers (top)
Here are some metrics used to measure the research impact of researchers:
- Number of publications
refers to the total number of publications a researcher has published
in the researcher’s lifetime or within a defined period of time (e.g.
last five years).
This number is often used as an indicator of the researcher’s productivity.
- Number of citations received from publications
refers to the total number of times a researcher’s work has been cited
by other research publications. The publications can be based on the
entire collection of published work by a researcher or the publications
within a defined period (e.g. last five years). This number is often
used as an indicator to measure the quality of research. The assumption
is that the greater the impact of the research, the more citation it
h-index is a number used to measure the productivity and influence of a researcher.
Definition of h-index: a researcher with an index of h has published h papers, each of which has been cited at least h times.
(i.e. A researcher with an index of 5 has published 5 papers, each of which has been cited at least 5 times.)
3. Research Impact of Journals (top)
Here are some metrics you can use to rank the journals by measuring the impact of these journals:
- Journal Impact Factor
Impact Factor (IF) of a journal is the average number of times articles
from the journal published in the past two years have been cited in the
Journal Citation Report* Year.
If Journal A has an impact factor of 5, on average, the articles
published in Journal A within the last 2 years have been cited 5 times.
publications in journals with higher IF may have higher chances of
being cited as compared to publications published in journals with
relatively lower IF.Researchers often use IF to help them decide where they should publish their research. It
is important to note that IF measures the impact of a journal and does
not measure the researchers publishing in the journal. Institutions
often use IF as an indication to evaluate their researchers on the
assumption that papers published in these journals of high IF are of
higher quality and have higher chances of being cited.
- 5-year Impact Factor
5-year IF is the average number of times articles from a journal
published in the last five years have been cited in the JCR year (as
compared to the last 2 years for IF). The
5-year IF may be more appropriate for subject disciplines where it may
take longer than two years to disseminate and respond to published works
(e.g. Arts and Humanities). The 5-year IF is also good for the
researchers to see how citation patterns of the journal changes over a
longer period of time.
- Cited half-life
This refers to the median age of the articles that were cited in the JCR year.
The Cited Half-Life of Journal A in 2011 is 7.4. This means that it
takes 7.4 years for the papers published in Journal A in the year 2011
to reach 50% of their total lifetime citations.
The Cited-Half Life
shows if the journal has a good track record and shows how long content
in the journal is still being referred to after publication.
- Immediacy Index
Immediacy Index refers to the number of times a paper published in a year is cited within that same year.
Immediacy Index of Journal A is 2.24. This means that the papers
Journal A published in the year 2011 were cited, on average, 2.24 times
*Journal Citation Report (JCR) is
available via Web of Knowledge. JCR lets you search across the Science
or Social Sciences Edition to obtain journal information based on
citation data. More details here.
Citations and Research Impact