  Bibliometric indicators are increasingly used in support of decisions for
recruitment, career advancement, rewarding and selective funding for
scientists. Given the importance of the applications, bibliometricians are
obligated to carry out empirical testing of the robustness of the indicators,
in simulations of real contexts. In this work we compare the results of
national-scale research assessments at the individual level, based on three
different indexes: the h-index, g-index and "fractional scientific strength",
or FSS, an indicator previously proposed by the authors. For each index, we
construct and compare rankings lists of all Italian academic researchers
working in the hard sciences over the period 2001-2005. The analysis quantifies
the shifts in ranks that occur when researchers' productivity rankings by
simple indicators such as h- or g-index are compared with that by more accurate
FSS.
