Training in conservation of weight

After a pretest for conservation of weight, 48 five- to eight-year old nonconservers were given one of four training treatments. Training problems involved deformations and additions or subtractions of material, using pairs of clay objects. The training variables were presence vs absence of reinforcement, and active participation vs passive observation by S. As measured by a posttest, which included both clay problems and transfer problems using a discontinuous material, reinforcement facilitated acquisition of conservation of weight, but active participation had no effect. Results were interpreted as showing that a principle of conservation of weight had been learned through the use of reinforcement in the training procedures used.