In Piaget's terminology, awareness that two objects which are equal according to a certain measure (such as length, weight, or quantity) remain equal in the face of perceptual alteration (for example, a change in shape) so long as nothing has been added to or taken away from either object.
Piaget?s term for the ability of the child to recognize that certain properties of objects (such as mass, volume, number) do not change despite transformations in the appearance of the objects. See also preoperational stage.
Conservation refers to an ability in logical thinking according to the psychologist Jean Piaget who developed four stages in cognitive development. By the third stage, the Concrete operational stage, the child of age 7-11 has mastered this ability, to logically determine that a certain quantity will remain the same despite adjustment of the container, shape, or apparent size.