Probing The Cause Of Chemical Preconception And Altermative Concepts Of Junior School Students

Scientific preconception (be abbreviated to preconception) is the cognition that students form before accepting formal scientific concepts education, through the perception of daily phenomenon of life, and long-term experience accumulated and studying formed with the distinguishing type, is also called "daily concept", "individual concept" or "substitute concept" etc. Some of them are consistent with scientific concept; some are not compatible with them, which are called "alternative concept " that diverge and deviate from scientific concept.According to the contemporary construclism, student's study is the process of actively constructing on information accepted from environment by students, and original knowledge, experience and thinking style play an important role in this process. If they are correct and rational, they can help the students to assimilate the new scientific concept and construct the new cognitive structure; If they are unreasonable and unscientific, they must hamper the students to understand the relevant scientific concept, even produce new wrong cognition and understanding in interaction of original knowledge and new one, which result in further erroneous constructing of cognition structure.Many researches shows that, when they learn new concepts, students try to connect text content with their original knowledge that is individual point and modle. and they think them are "practicable"and "reasonable"in explaining and judging the daily phenomena and facts, so they often hardly give up or change them, and among teaching practice, many students are often unable to use the scientific concept to explain the phenomenon and question of daily, or refuse to change their ideas despite of being taught repeatedly, which is often a headache for teachers, especially science teachers. And students' original views and points are potential, spontaneous and unobservable. so, to our teaching, how to inquire naive, not overall and wrong ideas that exist in stuedents' minds, and which teaching tactics can be adopde to help students change them, have been urgent problems to be solved.Since the middle period of the seventies of the 20th century, in the relevant natural education of science seminars that held both at home and abroad, probing into how to correct students' unscientific cognition has been discussed many times, and knowing the students' intuitive ideas on scientific concept and inquiring unscientific cognition in their cognitive structure, have been important research subjects in the education of science field in recently years, too. But seen from document materials, many of domestic and international researches on students' preconception, concentrates on "physics" and "living beings" subjects, and researches on students'chemistry preconception is a few. But a large number of these researches generally focus on probing into the cause of preconception and static of alternative concept transition from outside objective factors, and few of them pay close attention to the course and characteristic of student's thinking. So, under the guidance of humanism, probing into the cause of students' preconception and especially their alternative concept from the inner and external factor, has important theoretical and practical significance to the formation of students' scientific cognition, reveal the law of their preconception formation, richen and develop study theory.So. this text author systematically probed into students' preconception which they have already had before they accepted formal chemistry education, with the methods of questionnaires , teachers and students interviews , teaching experiment, the way and influence factors of preconception: Through spoken reports, homework analysis, the author analyzed the properties, information of influence factors and characteristics of alternative concept, and tentatively put forward teaching tactics and common course that change students' alternative concept, and based on above all. carried on teaching experiment. Just as Asubuel said: "The most important...