  Two approaches are outlined to characterize the fluctuation behavior of work
applied to a system by a slow change of a parameter. One approach uses the
adiabatic theorems of quantum and classical mechanics, the other one is based
on the behavior of the correlations of the generalized coordinate that is
conjugate to the changed parameter. Criteria are obtained under which the work
done on small thermally isolated as well as on open systems ceases to fluctuate
in a quasistatic process.
