For the second part of the question "Why H-index is considered more powerful than cumulative citations"

That is because using H-index has several advantages than other tools such as cumulative citations

Here is a list of advantages of the h-index

"• It is a mathematically simple index.

• It is a better index than total number of publications or total number of citations alone.

• It encourages high quality (or at least highly visible) work.

• The h-index can be applied to any level of aggregation. This means: not only to scientists but also to different groups of scientists, such as

all scientists belonging to a research institute, belonging to a university, even belonging to the same country. h-index and h-type indices

• It combines two types of activity (in the original setting this is citation impact and publications).

• Increasing the number of publications alone does not have an immediate effect on this index.

• It is a robust indicator in the sense that small errors in data collection have no or little effect.

• Single peaks (top publications) have hardly any influence on the h-index.

• In principle, any document type can be included.

• Publications that are hardly ever cited do not influence the h-index ."

(Source: Ronald Rousseau "Reflections on recent developments of the h-index and h-type indices"COLLNET JOURNAL OF SCIENTOMETRICS AND INFORMATION MANAGEMENT 2(1) JUNE 2008 )

Scopus H-index is considered more powerful

I also think that h-index given by Scopus is most reliable. The advantage of h-index is well summarized by Bornmann et al. (https://doi.org/10.1002/asi.20806) as follows:

The h index is seen to have the advantage that it gives a robust estimate of the broad impact of a scientist's cumulative research contributions (Hirsch, 2005). It combines number of publications and citation counts in a “balanced way” (Braun, Glänzel, & Schubert, 2005), being insensitive to a set of lowly cited (noncited) papers or to one or several highly cited papers. That means that the h index favors “those authors who produce a series of influential papers rather than those authors who either produce many papers that are soon forgotten or produce a few that are uncharacteristically influential” (Kelly & Jennions, 2006, p. 167). The h index can be used not only to determine the past productivity of a scientist, but it is also—as Hirsch (2007) ascertains in his most recent published study—better able than other bibliometric indicators to predict a scientist's future productivity (Ball, 2007). For this reason, Hirsch (2007) finds the h index “a useful indicator of scientific quality that can be profitably used (together with other criteria) to assist in academic appointment processes and to allocate research resources” (p. 19198). According to Glänzel (2006), another strength of the h index is that for the assessment of small paper sets (as was the case for the postdoctoral researchers examined in the present study) it is particularly well suited when “other, traditional bibliometric indicators often fail or at least were [sic!] their application proved usually problematic” (p. 320).

@ Prof Tatsuo Tabata

Thank you so much.

Very well informative comments described by Dr Tatsuo Tabata

I do agree with him and Dr Houda

SCOPUS H-Index is most reliable one.

Others H-Index are also available i.e. Google Scholar H-Index and Research Gate H-Index.

Scopus H-Index is most reliable than the others.

Dear Hom Nath Chalise,

Look the link, please.

https://ru.wikipedia.org/wiki/%D0%98%D0%BD%D0%B4%D0%B5%D0%BA%D1%81_%D0%A5%D0%B8%D1%80%D1%88%D0%B0

https://www.researchgate.net/post/which_h-index

Regards, Shafagat

Scopus H-Index is most reliable .

For the second part of the question "Why H-index is considered more powerful than cumulative citations"

That is because using H-index has several advantages than other tools such as cumulative citations

Here is a list of advantages of the h-index

"• It is a mathematically simple index.

• It is a better index than total number of publications or total number of citations alone.

• It encourages high quality (or at least highly visible) work.

• The h-index can be applied to any level of aggregation. This means: not only to scientists but also to different groups of scientists, such as

all scientists belonging to a research institute, belonging to a university, even belonging to the same country. h-index and h-type indices

• It combines two types of activity (in the original setting this is citation impact and publications).

• Increasing the number of publications alone does not have an immediate effect on this index.

• It is a robust indicator in the sense that small errors in data collection have no or little effect.

• Single peaks (top publications) have hardly any influence on the h-index.

• In principle, any document type can be included.

• Publications that are hardly ever cited do not influence the h-index ."

(Source: Ronald Rousseau "Reflections on recent developments of the h-index and h-type indices"COLLNET JOURNAL OF SCIENTOMETRICS AND INFORMATION MANAGEMENT 2(1) JUNE 2008 )

Interesting information.

@ Dear Dr Dhiaa Neama Jabbar,

Thank you so much for your time and wonderful information.

Regards

Hom

Why Scopus H-Index is more reliable than Google H Index? .

I disagree that any H-index calculated in database that retrieves only selected sources and papers can be count as reliable. H-index (citation) in Scopus only valid for Scopus retrieved papers. So if you have papers in non-Scopus sources and some people cite them, find them valuable (for example research published in other than English or even regional languages) - these citations will not count in Scopus H-index - so it means that your real H-index reflecting your REAL citation rate can only be calculated through the database that retrieves all of your research and that is Google Scholar. It is not perfect of course and sometimes retrieves not purely academic items but still for calculating real H-index is the most valid, relevant an realistic tool in my view. CORE for example, one of the most respectable research and education organisations in the world uses Google scholar H-index for their ranking.

Dr Jamila Mustafina , I go with your views.

Scopus is very selective and does not cover all citations. Google Scholar is also not reliable much and sometimes over-exaggerates!; i.e. sometimes it considers reports that are not peer-reviewed or just put in a random website as citation, while one may say these are not reliable citations (I can write a report and cite myself and upload it in a "searchable" website and then it is considered as a citation by google!).

So we cannot say which source is the perfect one for H-index reporting. But if authors themselves are honest to themselves and remove the "none-peer-reviewed" or repeated citations from their account in google, then we can rely on google scholar (I think google also can develop an algorithm for this to identify and separate "non-standard" and "repetitive" citations...)

As far as I have seen/heard, most funding agencies look at either Scopus or Web of Science for H-index assessment or consider these sources as most reliable ones. I have not heard/seen any of them looking at google scholar.