  We discuss some important issues concerning multiplicities in quark and gluon
jets in e+e- annihilation. In QCD the properties of a jet in general depend on
two scales, the energy and virtuality of the jet. Frequently theoretical
predictions apply to a situation where these scales coincide, while for
experimental data they are often different. Thus an analysis to extract e.g.
the asymptotic multiplicity ratio CF/CA between quark and gluon jets, needs a
carefully specified jet definition, together with a calculation of nonleading
corrections to the multiplicity evolution.
  We propose methods to systematically study the separate dependence upon the
two scales in experimental data and compare the results with theory. We present
jet finding algorithms which corresponds well to the theoretically considered
jets. We also show that recoil effects add corrections to the modified leading
log approximation which are quantitatively important, though formally
suppressed at high energies.
