ADRIANI, O (reprint author), IST NAZL FIS NUCL, FLORENCE, ITALY.
We present a study of the global event shape variables thrust and heavy jet mass, of energy-energy correlations and of jet multiplicities based on 250 000 hadronic Z0 decays. The data are compared to new QCD calculations including resummation of leading and next-to-leading logarithms to all orders. We determine the strong coupling constant alpha(s) (91.2 GeV) = 0.125 +/- 0.003 (exp) +/- 0.008 (theor). The first error is the experimental uncertainty. The second error is due to hadronization uncertainties and approximations in the calculations of the higher order corrections.