What is it?
The h-index is a way to measure the impact of a researcher's work and is based on the number of times that researcher's work is cited. Web of Science and Google Scholar are both capable of tracking citations, and therefore can be used to calculate a researcher's h-index.
While Web of Science and Google Scholar will automatically calculate an h-index, it is useful to know how to calculate it manually as well. The h-index can be calculated by locating all published works in a specific database (such as Web of Science or Google Scholar) and organizing the works in descending order by number of citations. The last article in the list where the number of its citations is equal or greater to the article's numbered position on the list is the h-index. To illustrate, in the example below, the h-index would be 4, as the author has published 4 articles that have been cited at least 4 times each.
How to find your h-index in Web of Scholar and Google Science
H-indexes can be calculated using any citation-tracking database, two of which are Web of Science and Google Scholar. Web of Science searches over 12,000 scholarly journals and other material (about Web of Science). Google Scholar is an index of scholarly literature that includes many disciplines and sources drawn from "academic publishers, professional societies, online repositories, universities, and other websites" (about Google Scholar).
A comparison of pros and cons of using Web of Science and Google Scholar to calculate the h-index can be found here.
Web of Science
- The University of Windsor has a subscription to Web of Science. It can be accessed anywhere on campus, as well as off campus when logged into your UWindsor account.
- Search for articles
- Click Create Citation Reports in the results page. The citation report provides statistics for how many times each article has been cited. Detailed instructions on Web of Science citation reports can be found here.
- The Citation Report will provide a list of all articles in the search results and the number of times each article has been cited, sorted in descending order, which makes it easy to calculate the h-index. The Citation Report instructions include an example of an h-index found using the Citation Report. Review the list for any duplications.
- Unlike Google Scholar, on Web of Science a new search must be performed every time you want to calculate the h-index using this database (although there is the option to save searches). It is important to periodically conduct a new search to ensure that the h-index is as recent and accurate as possible.
- Google Scholar can be accessed freely from anywhere, although not all of the results it returns may be fully accessible.
Search for articles
- Search articles one at a time by title, or capture multiple articles by searching by author name and refining the search results. Google Scholar search tips can be found here.
The Google Scholar citation profile allows researchers to create a profile which keeps metrics on the number of citations received, including who is citing articles as well as tracking citations over time. Once articles are added to a profile, the h-index can be calculated automatically.
- Pro: Once articles are added to the citation profile, an option is available to have Google Scholar automatically track future citation metrics for these articles.
- Con: When a citation profile is created, Google Scholar will suggest articles that may belong to you. However, it is possible that not all articles will be suggested automatically. A manual search is the best way to be sure that no articles have been overlooked.
- The Google Scholar citation profile allows researchers to create a profile which keeps metrics on the number of citations received, including who is citing articles as well as tracking citations over time. Once articles are added to a profile, the h-index can be calculated automatically.
- Once articles have been added to the citation profile, Google Scholar will calculate the h-index automatically.
- The h-index can also be calculated manually by arranging articles in descending order based on the number of citations they have received.
- Google Scholar provides the option to automatically track citations for articles that have been added to the citation profile. However, it is important to continue to manually search and add any new articles to the citation profile, as well as monitoring to ensure that all known citations are captured.
Why are they different?
It is possible for the h-index to vary from database to database, which means that a researcher will have a different h-index based on the one they use. For instance, Google Scholar tends to show a higher h-index than Web of Science. This is because each database searches from its own index, and Web of Science's index is not as extensive and does not include all of the same journals as Google Scholar, and therefore may not include as many of a researcher's works. Additionally, Web of Science has different subscription levels which determine the extent of access granted to their index.