A scientometrics law about co-authors and their ranking. The co-author core

摘要

Rather than "measuring" a scientist impact through the number of citationswhich his/her published work can have generated, isn't it more appropriate toconsider his/her value through his/her scientific network performanceillustrated by his/her co-author role, thus focussing on his/her jointpublications, - and their impact through citations? Whence, on one hand, thispaper very briefly examines bibliometric laws, like the $h$-index andsubsequent debate about co-authorship effects, but on the other hand, proposesa measure of collaborative work through a new index. Based on data about thepublication output of a specific research group, a new bibliometric law isfound. Let a co-author $C$ have written $J$ (joint) publications with one or severalcolleagues. Rank all the co-authors of that individual according to theirnumber of joint publications, giving a rank $r$ to each co-author, startingwith $r=1$ for the most prolific. It is empirically found that a very simple relationship holds between thenumber of joint publications $J$ by coauthors and their rank of importance,i.e. $J \propto 1/r$. Thereafter, in the same spirit as for the Hirsch core,one can define a "co-author core", and introduce indices operating on anauthor. It is emphasized that the new index has a quite different(philosophical) perspective that the $h$-index. In the present case, onefocusses on "relevant" persons rather than on "relevant" publications. Although the numerical discussion is based on one case, there is little doubtthat the law can be verified in many other situations. Therefore, variants andgeneralizations could be later produced in order to quantify co-author roles,in a temporary or long lasting stable team(s), and lead to criteria aboutfunding, career measurements or even induce career strategies.