I edited my paper. someone please check it. Thanks!

I posted this paper 2days ago. Thanksfully Julielai poited out some of mistakes. so I edited them but i'm still not sure i did it correctly someone plase review it. Thanks!


Piaget’s theory postulates that there are four major stages in cognitive development. The preoperational stage is the second stage that age from about two to seven. In this period, children are learning languages and start to use symbolic thought and memory skills. However they have not yet developed conservation and reversibility. “Conservation is the principle that properties such as mass, volume, and number remain the same despite changes in the forms of objects.” (Textbook page:150) They are also egocentric; their view of the world is very self-centered.

During the last weekend, I visited my friend’s house. He has a daughter named Jina. She is three year and two month old. Before dinner, I conducted one of Piaget’s conservation experiments. I picked out two identical clear glasses and filled them with the same amount of water. Then I asked her, “Jina, do you see those two cups with water in it? Which cup has more water in it, or they have the same amount of water?” She said they have same amount of water in the two cups. After she answered my question, I brought a cup that is more narrow and tall. Then I poured all the water from one of two cups that I just showed to her. I asked her again. “Jina, which cup has more water in it, or are they have the same amount of water?” she said the narrow and tall cup has more water in it than the other cup even though they have the same amount.

Jina was not able to conserve because lack of conservation and reversibility. She focused on only one dimension. She noticed the change in level of water but did not notice that other aspects of the situation changed simultaneously.