  An update of measurements of the strong coupling constant $\alpha_s$ is
given, representing the status of September 2002. The results convincingly
prove the energy dependence of $\alpha_s$ and are in excellent agreement with
the expectations of Quantum Chromodynamics, QCD. Evolving all results to the
rest energy of the $Z^0$ boson, the new world average of $\alpha_s(M_Z)$ is
determined from measurements which are based on QCD calculations in complete
NNLO perturbation theory, giving $$ \alpha_s(M_Z) = 0.1183 \pm 0.0027 . $$
