Observations and results
Did the basketball bounce much higher on the harder surface compared with the softer one?
One factor that can affect the basketball's collision with the ground is the type of surface the ball collides with. When a basketball bounces off of a surface, some of its energy is absorbed by that surface. Some surfaces absorb more energy than others do. (How much energy gets absorbed determines how much energy a player has to put back into the ball to keep it bouncing.) A hard surface, such as concrete, absorbs less energy compared with a soft surface, such as a carpeted floor. The more energy absorbed by the surface, the less that remains in the ball for it to bounce. This is why you should have seen that when you bounced the basketball on a relatively hard surface it bounced higher (it lost less energy) compared with when it was bounced on a softer surface (where it lost more energy). For example, depending on the type of basketball and surface, you may have seen the ball bounce about 15 inches high on carpet and about 25 inches high on concrete.
More to explore
Physics of Dribbling a Basketball, from Physics
Elastic and Inelastic Collisions, from HyperPhysics, Georgia State University
Fun, Science Activities for You and Your Family, from Science Buddies
Bouncing Basketballs: How Much Energy Does Dribbling Take?, from Science Buddies