QCD studies with e+e- annihilation data at 172-189 GeV                         
  
     We have studied hadronic events from e+e- annihilation data at            
     centre-of-mass energies of 172, 183 and 189~GeV.                          
     We present distributions of event shape variables, charged particle       
     multiplicity and momentum, measured separately in the three data          
     samples.  From these we extract measurements of the                       
     strong coupling strength, the mean charged particle multiplicity,         
     and the peak position in the ln(1/x) distribution.                        
     In general the data are described well by analytic QCD                    
     calculations and Monte Carlo models.                                      
  
 Parallel session :3                   
 Plenary  session :11