An -moment is a linear
combination of the expected values of order statistics used to summarize the location,
scale, and shape of a probability distribution. If
denotes the
th order statistic in an
independent sample of size
,
then the
th
population
-moment
is
In particular,
is the mean,
measures scale, and the ratios
and
measure L-skewness and L-kurtosis, respectively.
Population L-moments are finite whenever the distribution has a finite mean,
and sample L-moments are generally less sensitive to extreme observations than conventional
sample moments.