  We propose a simple new index, named the $CI$-index, based on the Choquet
integral to characterize the scientific output of researchers. This index is an
improvement of the $A$-index and $R$-index and has a notable feature that
highly cited papers have highly weights and lowly cited papers have lowly
weights. In applications many researchers may have the same $h$-index,
$g$-index or $R$-index. The $CI$-index can be provided an effective method of
distinguish among such researchers.
