G-index
Encyclopedia
The g-index is an index for quantifying scientific productivity based on publication record. It was suggested in 2006 by Leo Egghe.
The index is calculated based on the distribution of citation
s received by a given researcher's publications:
In simple terms, this means that an author that produces n articles is expected to have, on average, n citations for each of them, in to have a g-index of n. In this way, it is similar to the h-index, with the difference that the number of citations per article is not explicit.
The g-index has been characterized in terms of three natural axioms by Woeginger (2008).
The simplest of these three axioms states that by moving citations from weaker articles to stronger articles, one's research index should not decrease.
The g-index is highly correlated with the h-index
(Serenko 2010). However, these indices are conceptually distinct, and the g-index attempts to address shortcomings of the h-index
. Like the h-index
, the g-index is a natural number
and thus lacks in discriminatory power. Therefore, Tol (2008) proposed a rational
generalisation.
Tol also proposed a collective g-index.
The index is calculated based on the distribution of citation
Citation
Broadly, a citation is a reference to a published or unpublished source . More precisely, a citation is an abbreviated alphanumeric expression Broadly, a citation is a reference to a published or unpublished source (not always the original source). More precisely, a citation is an abbreviated...
s received by a given researcher's publications:
- 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.
In simple terms, this means that an author that produces n articles is expected to have, on average, n citations for each of them, in to have a g-index of n. In this way, it is similar to the h-index, with the difference that the number of citations per article is not explicit.
The g-index has been characterized in terms of three natural axioms by Woeginger (2008).
The simplest of these three axioms states that by moving citations from weaker articles to stronger articles, one's research index should not decrease.
The g-index is highly correlated with the h-index
H-index
The h-index is an index that attempts to measure both the productivity and impact of the published work of a scientist or scholar. The index is based on the set of the scientist's most cited papers and the number of citations that they have received in other publications...
(Serenko 2010). However, these indices are conceptually distinct, and the g-index attempts to address shortcomings of the h-index
H-index
The h-index is an index that attempts to measure both the productivity and impact of the published work of a scientist or scholar. The index is based on the set of the scientist's most cited papers and the number of citations that they have received in other publications...
. Like the h-index
H-index
The h-index is an index that attempts to measure both the productivity and impact of the published work of a scientist or scholar. The index is based on the set of the scientist's most cited papers and the number of citations that they have received in other publications...
, the g-index is a natural number
Natural number
In mathematics, the natural numbers are the ordinary whole numbers used for counting and ordering . These purposes are related to the linguistic notions of cardinal and ordinal numbers, respectively...
and thus lacks in discriminatory power. Therefore, Tol (2008) proposed a rational
Rational number
In mathematics, a rational number is any number that can be expressed as the quotient or fraction a/b of two integers, with the denominator b not equal to zero. Since b may be equal to 1, every integer is a rational number...
generalisation.
Tol also proposed a collective g-index.
- Given a set of researchers ranked in decreasing order of their g-index, the g1-index is the (unique) largest number such that the top g1 researchers have on average at least a g-index of g1.