The discovery of the W and Z gauge bosons at the Spp-barS in 1983
marked the beginning of direct electroweak measurements at a hadron machine.
These measurements vindicated the three level predictions of the Standard
Model.  The new generation of hadron collider machines now have data of such
precision that the electroweak measurements are probing the quantum
corrections to the Standard Model.  The importance of these quantum
corrections was recognised in the award of the 1999 Nobel Prize.