  This paper contributes to the quest for an operational definition of
'research excellence' and proposes a translation of the excellence concept into
a bibliometric indicator. Starting from a textual analysis of funding program
calls aimed at individual researchers and from the challenges for an indicator
at this level in particular, a new type of indicator is proposed. The Impact
Vitality indicator [RONS & AMEZ, 2008] reflects the vitality of the impact of a
researcher's publication output, based on the change in volume over time of the
citing publications. The introduced metric is shown to posses attractive
operational characteristics and meets a number of criteria which are desirable
when comparing individual researchers. The validity of one of the possible
indicator variants is tested using a small dataset of applicants for a senior
full time Research Fellowship. Options for further research involve testing
various indicator variants on larger samples linked to different kinds of
evaluations.
