Research On Evaluating And Changing Junior Middle School Students' Misconceptions Of Photosynthesis

Science conception is the basic unit of science knowledge composition, and the basis of science knowledge structure. However, scientific research shows that students'prior knowledge and ideas can influence science conceptions' formation, established and development. Before learning the formal science conception, students'mind not bank, they have already had their own opinions and understandings of natural phenomena and things in life by day-to-day communication and personal experience. However, some of the students'origial ideas are in line with scientists'understanding, but some are different from scientists'understanding. Ideas that are not the same as scientists' are called misconceptions. Misconceptions are extentive and obstinate. They would hinder students' comprehension of the right conception. Therefore, students'misconceptions should be fully understanded in science teaching, and design teaching strategies to promote transformation of misconception. It becomes the key to improve science teaching quality. Photosynthesis conception is abstract. It is considered one of the hardest conceptions to understand. Students have many photosynthesis misconceptions. At abroad and in taiwan, many educators have done lots of research on photosynthesis misconceptions, while continental area of china have done little on them.Based on the above background, we carry out the research on evaluating and changing junior middle school students' misconceptions of photosynthesis. Focusing on it, we fulfill following three aspects.First, based on collecting and sorting out related literature about misconception and conceptual change, we discuss the characteristics, causes and research methods of misconception, expound the theory of conceptual change, and clarify the research foundation.Second, based on summarizing the researches on photosynthesis misconception at home and abroad, we develop two-tier diagnostic assessment instrument to detect what misconceptions of photosynthesis of junior middle school students have, and analyse the investigation results.Third, based on the analysis of the investigation results, we discuss the differences between male and female students in understanding photosynthesis conception to see whether gender will have significant influence on it, and find out the causes of photosynthesis misconceptions. Then we put forward some teaching strategies to promote conceptual change of photosynthesis misconception.The results show that junior middle school students have serious misconceptions of photosynthesis in the definition, required raw materials, condition, reaction sites, products, substance, significance and relationship with respiration; There are almost no significant differences between the mean score of the male and female middle school students; There are seven causes to photosynthesis misconceptions of middle school students, which are daily life experience and observation, human-centered view of the surrounding environment, inappropriate analogies, not comprehensively understand the conception of photosynthesis, formal or informal teaching and teaching materials, lacking of discipline backgrounds knowledge, and intuition and imagination.According to the research and current teaching practice, we think that reasonably applying some teaching strategies such as history-cognitive analysis, concept map, comparative, cooperative teaching and object teaching and so on into photosynthesis conception teaching will effectively promote students to change misconceptions of photosynthesis, then improve the quality of photosynthesis conception teaching.