H index can be used to evaluate the quantity and level of academic output of researchers. If the author's Np paper H is cited by H at least, and the other (Np-h) paper is cited by H, the scientist index is H, and each paper is cited at most once.

G index is the derivative index of H index. First of all, you need to draw a chart with the same index as the graph H, add up the total number of references of items exceeding the H score limit, and then find the average value of the subset of the reference set. If the author has some articles with high citation rate in part H listed by her, they will make this person's G score much higher than his H score.

If the H score is 5, it means that the author has at least 5 papers, and each paper has been cited at least 5 times; If the H score is 10, it means that he has 10 papers, and each paper has been cited at least 10 times.

Matters needing attention of G index:

After the papers are sorted by citation times, the maximum paper order G with at least g2 cumulative citations before sorting, that is, the cumulative citation times of papers in (g+ 1) order will be less than (g+ 1)2.

In 2006, Egghe put forward the G index, which is defined as: after the papers are sorted according to the number of citations, the maximum paper rank G with at least g2 cumulative citations, that is, the cumulative citations corresponding to (g+ 1) ranked papers will be less than (g+ 1)2. As can be seen from the definition, g≥h, the higher the number of citations, the greater the G index.