Teaching Design And Practical Research Based On The Triple Representation Of "Macro-Micro-Symbol" In Junior Middle School

Junior high school stage is an important stage of the formation of chemical thinking, but the domestic research on the chemistry of junior high school students is lack of research. Due to its own characteristics, the junior high school students are easy to accept macroscopic representation; Microscopic representation is difficult to imagine and understand because of its abstract nature; Chemical symbols, as a special language of chemistry, Most of junior high school students only have memorizing ability, but can not understand the meaning of symbols. Thus causes the psychological fear of chemistry. For this purpose, this study tries to find more suitable for junior high school instructional design to increase students' interest in chemistry, so that students can understand and master the chemical knowledge easily.Three kinds of representations based on the formation of students' mind: macroscopic representation, microscopic representation and symbolic representation. The three representations are not independent of each other, and can not be separated from each other. The three methods of characterization were combined and linked to form the thinking method of threefold representation. With the symbol as the carrier, the macro and micro sense are understood. The experimental phenomena are described of the chemical language of experimental phenomena by means of symbols, and the reasons of the macro phenomena are explained by using the microscopic representation. From different angles to study chemistry knowledge, so as to make a more comprehensive view of the chemical knowledge, construct the chemical knowledge network.The research of threefold representation of the foreign countries started earlier. The research of threefold representation in our country is mostly focused on the current situation, and the research on how to cultivate is less. Based on the theory of threefold representation, this study selected two classes of junior high school students with no significant difference. Control class focus on the use of the memory of the traditional instructional design, and the experimental class by threefold representation instructional design to cultivate students' triple characterization of thinking. After the control of teaching, by using the double deck questionnaire, the students' ability and consciousness of threefold representation were measured. The study found that:the formation of threefold representation ability is helpful to understand and master the chemical knowledge of junior middle school students. The junior middle school students have different ability to represent the different characterization methods. For threefold representation of the chemical learning thinking, students can be guided by the teacher to get. The instructional design of the threefold representation are effective to the students. For the junior high school chemistry instructional design, recommend the use of three kinds of combination of characterization. Teaching in the use of analogy, model, animation and other visual means to make The micro knowledge expressed by macro. With the chemical symbol as a carrier, emphasizing the significance of macro and micro chemical symbol, so as to guide students to fully understand. Pay attention to team cooperation experiment, describe the experimental phenomena observed into chemical symbols and use microscopic model to understand the nature of reaction.This study uses the double type questionnaire survey of students in the three representations ability and awareness of students were also investigated. Through the contrast teaching, this study provides specific instructional design for threefold representation. Guide the students to apply chemistry thinking of threefold representation to construction their chemical knowledge network.