The hallmark of this stage is conservation. The child understands that changing an object's appearance does not change its fundamental properties like volume, mass, or number.
To assess conservation of volume, use two identical containers of water. Pour one into a tall, thin glass and the other into a short, wide bowl. A child who has mastered conservation will state the amount of water is still the same.
A child in the previous preoperational stage will focus on only one dimension (centration), such as the height of the liquid, and insist the taller glass has more. This is an expected finding before age 7.
학습 참고용입니다. 실제 임상은 최신 지침과 소속 기관 프로토콜을 따르세요.