In relation to Piaget's theory, describe the preoperational thinkers' inability to conserve.

Conservation refers to the idea that the "amount" of some substance stays the same regardless of its shape or the number of pieces into which it is divided. For example a glass in water in different shaped containers. Children's thinking will feature: 1. Centration - where they focus on the most perceptually obvious aspect on an object or event and ignore other features. For example, height of the water in the glass. 2. Lack of transformation - which is the ability to mentally record the process of moving from one state to another, such as pouring the water from the 1st to the 3rd glass. To them it's a new and different container of liquid. 3. Lack of reversibility, which is the ability to mentally reverse the process of pouring the water from one glass to another.