Research On Teaching Strategy For Junior’ Optic Preconception Change

Physics preconception is the students’personal views to the nature and daily things around themselves formed before the scientific concept learning. Usually, it is not identical to scientific knowledge, sometimes appears in contradiction to scientific conception. Preconception takes the features of individual differences, discontinuity and stability, which can prevent students from constructing scientific concepts in the learning processes. In the past decades, preconception research has become one of most important part in scientific education field. In this article, the internal mechanism of students’scientific knowledge construction is illustrated, based on the theory of constructivism, in the knowledge, study and instruction thoughts respectively. Taking the conception change model proposed by Posner as the instruction, the conditions which should be satisfied so as to make the change happen are analyzed. There must be dissatisfaction with existing conceptions; a new conception must be intelligible; a new conception must appear initially plausible; a new concept should suggest the possibility of a fruitful research program. And then, these methods must be applied in the teaching processes. The teaching strategies to change students’preconception to scientific concept have been proposed, and applied in the teaching experiment.Before the teaching practice, the students’preconception on Optics had been summarized in nine points by the approaches of questionnaires, literature research and interviews, including’light and light source’,’light propagation’,’pinhole imaging’,’retraction and reflection’,’the formation of imaging of level crossing’,’light and eyes’,’colors’,’invisible light’,’lens’, which were used as the knowledge points to exam the students. Four junior classes in one school in Chang Sha were selected as experimental classes and contrast classes, respectively. Self-made papers were used to examine the students before the teaching of light; the results were analyzed by the Statistical Package for the Social Sciences (SPSS) software to construct a pre-teaching database. It was found that the experimental classes and contrast classes made little difference in examination results. Thus, the experiment was promised to be scientific and valid.The next step is teaching practice, which was made by the same teacher in experimental classes and contrast classes. Considering the preconception traits, teaching requirement, students’ conditions and teaching strategies, the instructional design for the experimental classes was made. Meanwhile, the contrast classes were taught in the conventional way. After the knowledge was taught, a test was carried out in the classes, and an after-teaching database was established.The test results of experimental classes were compared to the contrast classes’ according to the whole scores and knowledge points scores respectively. The experimental results demonstrated that under the same learning conditions, the instruction methods and teaching strategies had an direct influence on students’ concept change. The experimental classes took more scores, that is to say that our teaching strategies indeed made the sense. Therefore, by paying attention to students’ preconception, taking the teaching strategies based on the perception confliction, which could promote students’ change from mis-preconception to scientific concept. The teaching design against students’preconception can inspire students’interest and join in the teaching class more efficiently, thus the teaching goal can be achieved, which is an effective teaching method. The research on the teaching strategy for preconception change makes inspirations to physics teaching.