The Chemical Evolution of Galaxy Disks
  We discuss the main ingredients necessary to build models of chemical evolution of spiral galaxies and in particular the Milky Way galaxy. These ingredients include: the star formation rate, the initial mass function, the stellar yields and the gas flows. Then we discuss models for the chemical evolution of galaxy disks and compare their predictions with the main observational constraints available for the Milky Way and other spirals. We conclude that it is very likely that the disk of our Galaxy and other spirals formed through an ``inside-out'' mechanism, where the central parts collapsed much faster than the external ones. This mechanism has important consequences for the appearance of galaxy disks as a function of redshift. 
Francesca Matteucci (Trieste University)