The g-index gives more weight to highly-cited articles. To calculate the g-index: "[Given a set of articles] ranked in decreasing order of the number of citations that they received, the g-index is the (unique) largest number such that the top g articles received (together) at least g² citations."
g-index, proposed by Leo Egghe in his paper Theory and practice of the g-index, 2006, as an improvement to the h-index. The g-index gives more weight to highly-cited articles.
To calculate the g-index:
"[Given a set of articles] ranked in decreasing order of the number of citations that they received, the g-index is the (unique) largest number such that the top g articles received (together) at least g² citations."
Advantages of the g-index
Accounts for the performance of author's top articles.
Helps to make more apparent the difference between authors' respective impacts. The inflated vales of the g-index help to give credit to lowly-cited or non-cited papers while giving credit for highly cited papers.
Disadvantages of the g-index
Introduced in 2007, and the debate continues whether the g-index is superior to the h-index. It is not as widely accepted as the h-index.