The flight instructor and certificated private pilot student were practicing touch-and-go landings as part of a rental check out for the private flying club. The student stated that 'on first touch and go, lost control, plane went sharply to the right when tailwheel touched down. Then applied left rudder [and the airplane] went sharply left hitting runway light and runway marker. [The flight instructor] regained control, and I taxied back to hangar.'