  A general formalism to include experimental reaction cross sections into
calculations of stellar rates is presented. It also allows to assess the
maximally possible reduction of uncertainties in the stellar rates by
experiments. As an example for the application of the procedure, stellar
neutron capture reactivities from KADoNiS v0.3 are revised and the remaining
uncertainties shown. Many of the uncertainties in the stellar rates are larger
than those obtained experimentally. This has important consequences for
s-process models and the interpretation of meteoritic data because it allows
the rates of some reactions to vary within a larger range than previously
assumed.
