Bibliometrics: Metrics for your CV
It is extremely difficult to “measure” the impact of an individual researcher or a research group on the discipline or society. However, bibliometrics can help to broadly inform evaluation alongside qualitative, expert assessment and review.
Here are some examples on how metrics can be presented on a publication list:
How to improve your impact
A few easy to do and easily applied steps can raise the visibility of your publication:
- Always use the same name version consistently throughout your career, e.g. “John J. O’Sullivan”, NOT “J. J. O’Sullivan”, “John O’Sullivan”, “John James O’Sullivan”
- Use a standardised institutional affiliation and address e.g. University College Dublin, School of Mathematics and Statistics, Dublin, Ireland
- Collaborate with researchers in other institutions
- Deposit your publication in Research Repository UCD.
- Use SEO (search engine optimisation) by carefully selecting title and keywords for your publication
- Register for an ORCID to improve identifiability in databases
- Present preliminary research findings at meetings and conferences
- Join academic social networking sites, e.g. Humanities Commons, ResearchGate, LinkedIn
- Consider communicating information about your research via Twitter, blogs or other social media channels
Keeping track of your research
- Set up citation alerts for your publications in Web of Science, Scopus and Google Scholar
- Sign up on scholarly networking sites, list your publications there and track how often they have been viewed and who is following you.
- Use alternative metrics (Altmetrics) to track the impact of your research. Downloads, tweets, likes or mentions are indicators on how often you publication has been discussed.
The h-index (a.k.a. Hirsch index) is a combined measure of both productivity and impact, and means that your h most highly-cited articles have at least h citations each, e.g. a researcher's h-index will be 5 if 5 of his/her articles have been cited at least 5 times.
The h-index has a number of significant limitations:
- Academic disciplines differ in the average number of references per paper and the average number of papers published by each author
- The length of the academic career will impact the number of papers published and the amount of time papers have had to be cited. The h-index is therefore a less appropriate measure for early career researchers.
- There are different patterns of co-authorship in different disciplines.
- Individual highly cited papers may not be accurately reflected in an h-index.
For these reasons the h-index should be used with extreme caution, and should preferably be modified to account for career length and number of co-authors etc. (see box on alternative indices below).
The h-index can be calculated by using the following tools:
If multiple-authored articles are common within your discipline, your h-index may be relatively high. Your degree of contribution to each article, however, may be thought to diminish as your number of co-authors increases. The hi-index (aka individual h-index) takes the number of co-authors into account. Your hi-index is equal to your h-index divided by the average number of authors on the articles in your h core.
One of the strengths of the h-index—its insensitivity to highly-cited papers—could also be considered a weakness. That is, once an article has a sufficient number of citations to gain inclusion into the h core, additional citations are irrelevant. The g-index, in contrast, weights highly-cited papers more heavily. An index of g means that your g most highly-cited articles together have at least g-squared citations. Your g-index will always be equal to or greater than your h-index.
If you published a few highly-cited papers decades ago but are now inactive, your h-index may be higher than an established researcher who steadily continues to publish or a promising new researcher who is just beginning to gain recognition. The hc-index (AKA contemporary h-index) weights newer articles more heavily than older articles, so that articles lose their value over time. This allows a clearer picture of more recent levels of productivity and impact.
If your have been publishing for decades, your h-index will be higher than a researcher who has been publishing for only a few years. The m-index takes differences in career length into account, by dividing your h-index by the number of years that you have been publishing.
Several other alternative indices have also been proposed.