Two commonly used ideas in the development of citation-based research
performance indicators are the idea of normalizing citation counts based on a
field classification scheme and the idea of recursive citation weighing (like
in PageRank-inspired indicators). We combine these two ideas in a single
indicator, referred to as the recursive mean normalized citation score
indicator, and we study the validity of this indicator. Our empirical analysis
shows that the proposed indicator is highly sensitive to the field
classification scheme that is used.

We present an empirical comparison between two normalization mechanisms for
citation-based indicators of research performance. These mechanisms aim to
correct for the field and the year in which a publication was published. One
mechanism is applied in the current crown indicator of our institute. The other
mechanism is applied in the new crown indicator that our institute is planning
to adopt. We find that at high aggregation levels, such as at the level of
large institutes or at the level of countries, the differences between the two
mechanisms are very small.

We present a theoretical and empirical analysis of a number of bibliometric
indicators of journal performance. We focus on three indicators in particular,
namely the Eigenfactor indicator, the audience factor, and the influence weight
indicator. Our main finding is that the last two indicators can be regarded as
a kind of special cases of the first indicator. We also find that the three
indicators can be nicely characterized in terms of two properties.