A Primary Investigation On Children's Comprehension Of The Concept Of Gravity

Curriculum and really efficient instruction base on the full comprehension of students'original knowledge and experience. It is significant for science education to use students'original knowledge and experience to take suitable ways to make them know better about the scientific conceptions. So we should investigate students'ideas of the natural phenomena and know fully about their notions. This research, using the method of questionnaire and clinical interview, initiates a primary investigation on children's comprehension of the concept of gravity. The sample population is 92. These students who ranged from the 3rd grade to the 8th grade don't have any systematical knowledge of gravity in science class. The aim of this research is to know child's thinking world and help science teachers improve their teaching level.We have discovered that children have many alternative frameworks about gravity, for instance:"The air has no weight.""The object has no weight on the moon.""The heavier object falls to the ground first.""Center of gravity is always in the middle of the object.""The object which has big density is heavier than others.""There is no relation between weight and attractional force of the earth.""The attractional force of the earth is the same to the magnetic force.""Only the object falling down is subjected to the attractional force of the earth.""Only the object near the ground is subjected to the attractional force of the earth.""The attractional force of the earth exists only in the atmospheric layer.""The object which is nearer to the ground is subjected to the bigger attractional force of the earth.""The universal gravitation between two objects isn't equal to the each other, the smaller one is subjected to the bigger universal gravitation."After the statistical investigation of questionnaire, we find out the conclusion as follows: on one hand, along with the growth of age, the children get better comprehension of gravity, but the trend decelerating; on the other hand, there is a significant correlation between the cognition of force and the comprehension of gravity, also a significant correlation between the cognition of force-at-distance and the comprehension of gravity. If the children want to comprehend the concept of gravity, they have to know force and force-at-distance first. After the analysis of clinical interview, we divide the child's cognitive development level about center of gravity into 3 layers:â… Realizing no concept of center of gravityâ…¡Realizing no concept of center of gravity, but considering the factor of weightâ…¢Realizing the concept of center of gravity, and knowing the correlation between center of gravity and the distribution of weightIn the sample population, the number of layerâ… gradually decreases with the growth of child's age, the number of layerâ…¢presents an increased trend, but the number of layerâ…¡grows slowly. After the statistical investigation, we find that 53.3% students of group A are at the place of layerâ… . We can infer that it is wrong to ask the children ranged from the 3rd grade to the 4th grade to comprehend the concept of center of gravity by science inquiry-oriented teaching & learning, because it doesn't fit the existing cognitive development level of them. Also, 46.6% students of group B and 60% students of group C are at the place of layerâ…¢, so it is proper to ask the students ranged from the 5th grade to the 8th grade to comprehend the concept of center of gravity.Finally, we draw some inspirations from this research: first, science teaching materials and curriculum have to fit the cognition characteristic of the children; second, we must do our best to design inquiry-oriented teaching & learning activities so that the children can change their alternative frameworks into scientific conceptions; last, we should appeal the children's emotions of science.