A Microgenetic Study On The Students' Cognitive Development Of The Buoyancy In The Activity

It is Necessary for our teaching base on the full comprehension of students'original knowledge and experience, we investigate students'ideas of the natural phenomena and know fully about their notions before teaching. Generation and development of scientific concept have become one of the scientific education research hotspots in recent years. . But a lot of research focus on the characteristics and laws of the concept cognitive development in different ages of students ,and few of them discuss how the student's concept changing in the process of learning and activities . We need to know not only students'ideas of the natural phenomena and know fully about their notions before teaching. But also dynamic process of students'cognitive development. In order to design our teaching activities better.In this study, using the method of the microgenetic method. The sample population is 31 for study. These students who don't have any systematical knowledge of buoyancy in science class of a rural junior high school .The aim of this research is to know child's thinking how to change and help science teachers improve their teaching level.1, in the form of computing time on the buoyancy of the students in the cognitive, there is a lot of the former concept, the course of the study, found that the students before the concept as follows: level of strategy, hollow solid strategy, the air and force strategy, the ship model strategy, the proportion of the initial strategy, density strategy and other strategies.2, we can see that the event was density in the number of students overall strategy is an upward trend, that is, activities for the students to the cognitive development of buoyancy principle, through the interview process on the face of the analysis, we can know that that density, strategy is the cognitive premise. of the buoyancyIn this study, in the form of computing the period of only 48.3 percent of students in activities in the density of access strategy, but really to be able to master density strategy (for use during the five or more) of only five people, or the total number of test was 16.1%3, in the event scenario, the students who have ship model strategy t is very difficult to change strategy. It is enable for students to understand the buoyancy principle if not to change ship model strategy when we teaching buoyancy.In addition, the study's findings further validate the concept of change and repeat the characterization of the theory. And integrate research on the conclusions and recommendations the corresponding for teachingFinally, we reflects and summarizes on instruments, methods, data analysis, procedures and interviewees.