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Chemistry: Citation analysis & h-index

A guide to online and print resources in chemistry.

InCites Journal Citation Reports

If you are searching Web of Science, there are two ways to find out the impact factor of a journal.  The impact factor is a measurement that takes into account how many times the journal's articles are cited, and may reveal something about the journal's reputation.

1.  Go directly to InCites Journal Citation Reports, enter the journal title in the search box on the left, and click on search. On the left click on RANK. Q1 means 1st quartile, Q2 means 2nd quartile, etc.

2.  Search the Web of Science Core Collection by keyword/topic. Click on the journal name in the search results, or click on View Journal Impact in the article description. You'll see the impact factor, rank and quartile for the journal in the various categories to which the journal is assigned.  

Citation Analysis

Analyzing citation data is one way to measure research impact of individual articles and authors.

InCites Journal Citation ReportsEvaluate journals using citation data drawn from over 7,500 scholarly and technical journals. InCites Journal Citation Reports can show you the:

  • Most frequently cited journals in a field
  • Highest impact journals in a field

Web of Science (ISI)  Citations and abstracts from scholarly literature in the sciences, social sciences, arts, and humanities. Includes over 8,500 high impact research journals, conference proceedings, symposia, seminars, colloquia, workshops, and conventions also included. Cited reference searching allows you to track prior research, see who is citing your work, measure the influence of someone's work, and navigate forward, backward and through the literature of your discipline. Coverage 1975-present.  How to do Cited Reference Searching (video)

see also Finding the Impact Factor of a Journal

Impact factors of journals

The h-index

What is the h-index?

H-index stands for Hirsch index.  It is a measure of an individual's scientific research output. 

It was originally proposed by J.E. Hirsch.

If your h-index is 5, it means that you have 5 articles that have been cited at least 5 times.

However, one should also cite the source from which the h-index was derived, as in: "My h-index is 12, calculated on December 5, 2015, using Web of Science data from 1975-2015."

Hirsch believed the h-index was a better measure than one's "average citation rate."  Hirsch used Web of Science as the tool for his calculations.

See: Hirsch, J. E. (2005). An Index to Quantify an Individual's Scientific Research Output. Proceedings Of The National Academy Of Sciences Of The United States Of America, 102(46), 16569-16572.

How to calculate the h-index

 

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H-iindex -- how to calculate

See also: What is the h-index? 

The h-index can be calculated by searching for an author's name and creating a citation report in Web of Science. (In the Marked List, you will find the option to "Create Citation Report.")

I recommend the following short video from ISI which  will give you a concise introduction to calculating one's h-index. The video is called Citation Reports from the Web of Science.  (Watch from about :55 to 4:30 to see how to calculate the h-index)

Here are a few caveats about use of the h-index:

 

The h-index is intended to be comparable within the same field.  For example, it is not accurate to compare the h-index for an author in physics to one in math.

 

It is not accurate to compare two authors with very different publishing histories (one who is early in his or her career with one who is not, or one who publishes mainly in books with one who publishes mainly in journals). 

 

If you publish mainly in conference proceedings or in books, beware of calculating your h-index using Web of Science (Thomson Reuters sells an add-on product which includes conference proceedings, but it is not part of the NU subscription). Web of Science covers more than 10,000 journals in 3 indexes (Science Citation Index, Social Science Citation Index, and Humanities Citation Index); your h-index as calculated using Web of Science is based on the number of times your journal articles have been cited.

 

Because the h-index is dependent on the source of data it is a best practice to cite the source of data when providing an h-index. For example, one should say "My h-index is 17, calculated on June 15, 2017, using Web of Science data from 1975 to 2017."

 

If the researcher has a common last name, look carefully at each article in the search results to make sure the author is the correct one, or compare the results directly to the author's c.v. and eliminate any false hits before running the report.  Exercise caution in limiting by institution or work address; you may miss publications the researcher authored while at another (previous) institution.

 

The h-index depends on 1) the depth of the data file and 2) source of citation data.

 

Depth of the data file. Say, for example, that I had published 20 articles from 1960 to 2017 - with 9 published from 1960 to 1974 and 11 from 1975 to 2017. Since Northeastern University's access to data in Web of Science is from 1975 forward, only the 11 articles from 1975 forward (and the citations to those 11 articles) would be used in the h-index calculation.

 

The source of the citation data. Any set of citation data can have an h-index calculation (WoS, Scopus, Google Scholar). To produce an h-index one needs to:

a) sort a set of articles with times cited counts from most highly cited to least highly cited

b) number the articles so that the article with the most citations is article "1"

c) find the article whose number is equal to its citation count. That number would be the h-index.

 

As mentioned above, be sure to cite the source of data when providing an h-index. 

 

Thank you to Don Sechler of Web of Science for help in providing this information. 

Watch a short video on calculating the h-index and creating citation reports using Web of Science.  (Watch from about :55 to 4:30 to see how to calculate the h-index)

See more tutorials from Clarivate Analytics on using Web of Science.

Please contact me, Kathy Herrlich, if you have questions or need help in calculating the h-index.