H index depends largely on the author's academic career. The longer the general academic career, the more papers published and the higher the number of citations, so the higher the H index. For some authors who have just entered the academic field, the H index is relatively low, so the H index is greatly influenced by qualifications.
The H index will only go up, not down. Therefore, it cannot reflect the academic rest and retirement of scientists. The author's H index changes with the popularity of the professional field. Popular professional papers are easier to be cited, so the H index will be higher than that of unpopular professional authors.
Content of h index
H index was put forward by American physicist Hirsch in 2005 to "evaluate scientists' scientific research performance". Although the title of his original paper and Hirsch's description of the meaning of the H index are debatable, the H index has become popular all over the world in just a few years, and soon expanded to different fields such as journals, research teams, universities, research institutes, disciplines, countries, funds and research hotspots.