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| | Andrew Simcox is the name his parents gave him and he totally loves this title. To play lacross is one of the things she loves most. North Carolina is where we've been living for years and will never move. Invoicing is what I do.<br><br>Here is my weblog ... love psychic readings; [http://brazil.amor-amore.com/irboothe visit these guys], |
| The '''''g''-index''' is an index for quantifying [[scientific]] [[productivity]] based on [[scientific publication|publication]] record. It was suggested in 2006 by Leo Egghe.<ref name="Egghe">Egghe, Leo (2006) Theory and practise of the g-index, Scientometrics, vol. 69, No 1, pp. 131–152. {{DOI|10.1007/s11192-006-0144-7}}</ref>
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| The index is calculated based on the distribution of [[citation]]s received by a given researcher's publications:
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| :''Given a set of articles [[ranking|rank]]ed 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 g<sup>2</sup> citations.''
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| Just as with the [[h-index]], the g-index is a number which is the same for two different quantities:
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| g is (1) the number of highly cited articles, such that each of them has brought (2) on average g citations.
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| This is in fact a rewriting of the definition
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| :<math>g^2 \le \sum_{{i \le g }}c_{i} </math>
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| as
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| :<math>g \le \frac1g \sum_{{i\le g}}c_{i}</math>
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| [[File:Gindex1.jpg|thumb|275px|right| An example of a g-index (the raw citation data, plotted with stars, allows the h-index to also be extracted for comparison).]]
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| In other words, this means that in order to have a g-index of n an author that produces n articles should have, on average, n citations for each of them. Unlike the h-index, the g-index depends on the full citation count of very highly cited papers. Roughly, ''h'' is the number of papers of a quality threshold that rises as h rises; ''g'' allows citations from higher-cited papers to be used to bolster lower-cited papers in meeting this threshold. Therefore, in all cases g is at least h, and is in most cases higher.<ref name="Egghe"/> However, unlike the h-index, the g-index saturates whenever the average number of citations for all published papers exceeds the total number of published papers; the way it is defined, the g-index is not adapted to this situation.
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| The g-index has been characterized in terms of three natural axioms by Woeginger (2008).<ref>Woeginger, G.J. (2008) An axiomatic analysis of Egghe’s g-index, Journal of Informetrics, vol. 2, pp. 364–368. {{DOI|10.1016/j.joi.2008.05.002}}</ref> The simplest of these three axioms states that by moving citations from weaker articles to stronger articles, one's research index should not decrease. Like the [[h-index]], the g-index is a [[natural number]] and thus lacks in [[discriminatory power]]. Therefore, Tol (2008) proposed a [[rational number|rational]] generalisation.<ref>Tol, R.S.J. (2008) A rational, successive g-index applied to economics departments in Ireland, Journal of Informetrics, vol. 2, pp. 149–155. [http://ideas.repec.org/p/sgc/wpaper/147.html preprint]</ref> {{Clarify|reason=What rational generalization did he propose?|date=April 2010}}
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| Tol also proposed a collective g-index.
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| :''Given a set of researchers ranked in decreasing order of their g-index, the g<sub>1</sub>-index is the (unique) largest number such that the top g<sub>1</sub> researchers have on average at least a g-index of g<sub>1</sub>.''
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| ==See also==
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| * [[h-index]]
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| ==References==
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| <references/>
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| [[Category:Bibliometrics]]
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| [[Category:Academic publishing]]
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| [[Category:Index numbers]]
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Andrew Simcox is the name his parents gave him and he totally loves this title. To play lacross is one of the things she loves most. North Carolina is where we've been living for years and will never move. Invoicing is what I do.
Here is my weblog ... love psychic readings; visit these guys,