An author's impact on their field of research has traditionally been measured using the number of academic publications he or she has authored and the number of times these publications are cited by other researchers. Because of this, a simple way to illustrate an author's impact is to create a comprehensive list of their publications and the number of times they have been cited.

Citation analysis is traditionally used to measure author impact. Citation analysis compares the number of academic publications you have published to the number of times these publications have been cited by other researchers.

There are many metrics that have been developed  to measure the bibliographic impact of an individual. Each tool may produce varying results depending on the scope of its database. For an accurate picture of your research impact, use more than one tool and compare the results.

H-Index

What is it?

The h-index is the most common method of citation analysis, measuring the productivity and citation impact of publications. It was developed in 2005 by Jorge E. Hirsch and is sometimes referred to as the Hirsch index. 

The h-index is the number of papers (h) that have been cited h or more times. For example, if you have 10 papers that have been cited 10 or more times then you have an h-index of 10.  

Limitations of h-index 

• Disciplines are not comparable: Differences in productivity and citation practices exist across different fields. Because of this, the H-index of authors publishing in different disciplines are not comparable 

• H-index is very dependent on the length of an author’s career as the number of publications and citations increase over time. Early career researchers do not have an accurate g-index. These researchers typically have fewer publications, and it may take years for other authors to cite them.  However, the ‘“m parameter’” (division of the h-index by the scientific age of a scientist) was introduced to compare scientists at different career stages. 

• Prone to manipulation: the h-index can be manipulated through coercive or self-citation

G-Index

What is it?

The g-index is an alternative to the h-index. It puts a greater emphasis on an author’s most cited publications, allowing for differentiation between unique authors’ scholarly impact. Read more about the differences between the h-index and g-index. 

Limitations of g-index 

• The g-index is not as widely used as the h-index 

• Disciplines are not comparable: Differences in productivity and citation practices exist across different fields. Because of this, the H-index of authors publishing in different disciplines are not comparable 

• Similar to the h-index, this metric is very dependent on the length of an author’s career; the number of publications and citations increase over time. Early career researchers do not have an accurate g-index. These researchers typically have fewer publications, and it may take years for other authors to cite them.  

i10-Index

What is it?

Developed by Google Scholar, the i10-index tracks how many of your publications have been cited by at least 10 other publications. It is a more straightforward measurement than the h-index or g-index. The metric is currently only used by Google Scholar. 

Limitations 

• The i10 index focuses on a specific citation threshold (10 citations), which may not adequately reflect the quality or significance of research. It does not differentiate between papers with a few citations and those with a high impact. 

• Disciplines are not comparable: Differences in productivity and citation practices exist across different fields. Because of this, the H-index of authors publishing in different disciplines are not comparable 

• Since it only looks at papers that have received at least 10 citations, the i10 does not consider the long-term impact of research. Highly influential papers may take time to accumulate citations, and this metric may not capture their full impact.