In the individual assessment of a scientific performance, five scientometric indices have been used most: the h-index, the index g, the h-major index, the contemporary h-index and the normalized h-index. We propose an alternative index ("Index h-fac"), which considers positively the participation of the first author and that, by having a dynamic characteristic, continuously monitors his/her performance and is easily adaptable to particular or individual situations from different research groups. Results from the geometric mean between the original hindex as proposed by Hirsh and a correction factor ("fac", "first author commitment") and, in turn, this value is divided by the mean interval (