The flight instructor and student were performing a simulated soft-field takeoff from a paved runway. During the takeoff roll, the airplane rotated at about 65 mph, and began to drift left of the runway centerline. The student pilot then lowered the nose, and the airplane settled back onto the runway. The student then attempted to abort the takeoff and reduced the power to idle as the airplane exited the left side of the runway and struck a directional sign. The airplane sustained substantial damage to the left wing. The pilot reported that there were no preimpact mechanical failures or malfunctions that would have precluded normal operation. Winds at the time of the accident were recorded to be 10 knots at 340°, about 20 minutes prior to the accident were recorded to be variable at 6 knots, and about 40 minutes before the accident, the winds were 11 gusting to 16 knots at 150°.