Having publications in peer-reviewed journals is a main criterion for promotion, tenure or funding, yet not all co-authors are created equal. Jonathan D. Wren et al. (EMBO Rep. 8, 988–991; 2007) have investigated what readers think of the role of authors on the basis of their byline position and the total number of authors on a publication. Although first or last authors are generally apportioned most credit for the work, it is not known exactly how much authors are perceived to have contributed from their byline position.
Wren et al. surveyed chairs of promotion and tenure committees, and found that respondents felt that the first author in a three-person byline had made the greatest contribution to the work performed, whereas the last author deserved most credit for the conception and supervision of the project. According to this survey, adding authors to a publication apparently does not affect the relative overall credit afforded to the last author, but the perceived contributions of all other authors suffer a drop in value. (For more details, see Nautilus).
Nature 450, xiii; 29 November 2007