Before The Concept Of Junior High School Electric Power And Electric Power

Students have constructed their own cognitive system about the world before they study physics.In their cognitive system,some have correctly reflected the development law of the objects,others are not in accordance with the scientific concepts,we call the latter ones "pre-scientific conceptions",simply called pre-conceptions.With the development of the study, people have found that the students' pre-conceptions had hindered the learning obviously.So, detect the students'pre-conceptions and take measures to transform the pre-conceptions according to these,that is of great significance to physical teaching of the junior middle schools.This research uses the constructivism as the guideline,the hand-made qusetionnaire of the the middle school students' learnimg of electric work,Joule law and electric power as the instrument,investigates 131 students,and gets 18 typical pre-conceptions in the electric work,Joule law and electric power.On this basis,the author interviews 3 representative students, analyzes the characteristics and reasons of the pre-conceptions,and puts forward to the teaching strategies of transforming the pre-conceptions accordingly at last.The research indicates that:1.Junior high school students have pre-conceptions in electric work,Joule law and electric power to some extent,there is a gap in the transformation from the pre-conception to the scientific conception among the different classes,teacher play an important role during this process,at the same time other factors impact the transformation of the pre-conception yet;it is no significance between the boys and the girls thougn the latter are better than the former.2.Combining the explanations of the questionnaire and the interview of the students,we summarize 5 features about the pre-conception:①obstinate;②latent;③spontaneous;④extensive;⑤negative influential.On this basis we summarize 5 reasons of forming the pre-conceptions in electric work,Joule law and electric power:①the knowledge in these is comprehensive;②the existing life factors affect the students obviously;③physical formula is affected by mathematics;④more attention is paid to quantitative calculation than comprehension of conception;⑤the effect of test is important.3.Through interview,we discover that more attention is paid to accumulation of the scientific knowledge than the transformation of the pre-conceptions under the traditional teaching method,scientific knowledge and pre-conceptio have co-existed in the brain of the students,pre-conceptions have not disappeared because of the appearance of scientific knowledge,in some cases the pre-conceptios show an increasing trend.On the basis of the above-mentioned research,Taking into account the actual situation in junior middle schools,we propose some pieces of advice:①emphasize the concept of teaching; ②use the teaching strategy of mastery immediately;③make use of origal physical problem in transforming the pre-concept;④strengthen the experiment;⑤understand the relationship between the mathematics and physical concepts correctly.