h-index
The h-index is an author-level metric that measures both the productivity(no. of papers) and citation impact( no. of times cited) of the publications of a scientist or scholar to provide “an estimate of the importance, significance, and broad impact of a scientist’s cumulative research contributions.
A tool to measure an author's productivity and impact of published work.
The h-index is defined as the maximum value of h such that the given author/journal has published h papers that have each been cited at least h times.
Proposed by Jorge E. Hirsch in 2005
Calculation is based on the researcher's most cited papers and the number of citations that they have received (were these two numbers meet)
Example: If a researcher has 15 papers, each of which has at least 15 citations, their h-index is 15.
- Comparing researchers of similar career length.
- Comparing researchers in a similar field, subject, or Department, and who publish in the same journal categories.
- Obtaining a focused snapshot of a researcher’s performance.
Advantage of h-index
- Evaluates both qualitatively (impact factor or citations) and quantitatively (number of articles) and does not have the disadvantages of other ranking indices such as counting the total number of articles or the total number of citations.
- The Hirsch index provides a strong evaluation of the impact of a researcher’s scientific articles, meaning that it ignores low-citation or no-citation articles, or high-citation articles in computation.
- This index can be a good benchmark for evaluating researchers who have had a significant impact on scientific participation but their scientific work has not been given the opportunity using conventional scientometric channels.
- The data needed for computation of this index is easily accessible through the ISI, Scopus, and Google Scholar databases without the need for any information processing.
Disadvantages
The number of authors of an article and the contribution each has to the research is not determined by this index.
If a researcher has a limited number of papers but they are highly cited, the H-index will not be high
A researcher can cite his or her previous research many times (self-citation) and this can influence his or her H-index and lead to a false result.
i10 index
Created by Google Scholar and used in Google's My Citations feature.
i10-Index = the number of publications with at least 10 citations.
This very simple measure is only used by Google Scholar, and is another way to help gauge the productivity of a scholar.
Advantages
Very simple and straightforward to calculate
My Citations in Google Scholar is free and easy to use
Disadvantages
Used only in Google Scholar
Impact factor (IF)
Impact factor (IF) is a measure of the number of times an average paper in a journal is cited, during a year. Clarivate Analytics releases the Journal Impact Factors annually as part of the Web of Science Journal Citation Reports®. Only journals listed in the Science Citation Index Expanded® (SCIE) and Social Sciences Citation Index® (SSCI) receive an Impact Factor.
Impact Factors are used to measure the importance of a journal by
calculating the number of times selected articles are cited within a
particular year. Hence, the higher the number of citations or articles
coming from a particular journal or, impact factor or, the higher it is ranked.
IF is also a powerful tool if you want to compare journals in the subject category.
How Impact Factor is Calculated?
The calculation is based on a two-year period and involves dividing the number of times articles were cited by the number of articles that are citable.
Measuring a Journal Impact Factor:
- Use journal metrics to understand the impact of a journal:
- CiteScore metrics – helps to measure journal citation impact. Free, comprehensive, transparent and current metrics calculated using data from Scopus®, the largest abstract and citation database of peer-reviewed literature.
- SJR – or SCImago Journal Rank, is based on the concept of a transfer of prestige between journals via their citation links.
- SNIP – or Source Normalized Impact per Paper, is a sophisticated metric that accounts for field-specific differences in citation practices.
- JIF – or Journal Impact Factor is calculated by Clarivate Analytics as the average of the sum of the citations received in a given year to a journal’s previous two years of publications, divided by the sum of “citable” publications in the previous two years.
- H-index – Although originally conceived as an author-level metric, the H-index has been being applied to higher-order aggregations of research publications, including journals.
