Case Study Of The Unit Teaching Of Chemistry Based On Big Idea In Junior High School

The "Compulsory Education Curriculum Standards（2022 Edition）" emphasizes in "Course Concepts and Design Ideas" that it is necessary to "focus on the transformation of discipline education methods,deepen the reform of chemistry classroom teaching,and design and implement unit overall teaching based on the construction of big idea".The big idea is a core concept that integrates the three meanings of epistemology,methodology and axiology and is abstracted to reflect the logical structure of the discipline and the essence of the discipline.Because big idea has a wide range of applicability and explanatory power,they have lasting value and transfer value beyond the classroom.Therefore,the construction of big idea is an inevitable requirement to improve students’ problem-solving ability and develop students’ core literacy of disciplines.Since the formation of students’ big idea is a long-term process,the teaching content organized around the big idea can’t be completed in one lesson,and the teacher needs to plan the teaching content formed around the big concept as a whole in the form of "units".Qiquan Zhong thinks that"Unit Teaching based on the development of students’ core literacy is a fulcrum for the transformation of classrooms".It can be seen that in order to promote students to construct big idea,unit teaching must be advocated.However,the data shows that the current unit teaching research focusing on big idea in the field of chemistry is not in-depth enough.Therefore,this paper is based on junior high school chemistry,using case study as the main method to carry out related research.First of all,this paper defines the connotation of unit,unit teaching and big idea;analyzes the requirements of unit theme determination focusing on big idea,the principle of unit content selection and construction method;studies the unit teaching design process based on big idea,and discusses Requirements and strategies for the design of unit teaching objectives,unit teaching structure,and unit teaching activities.Secondly,through questionnaires,interviews,etc.,the implementation status and influencing factors of unit teaching for junior high school chemistry teachers are explored.The investigation results show that:（1）Junior high school chemistry teachers generally agree with the function of unit teaching,but don’t understand deeply;（2）Junior high school chemistry teachers need to deepen their understanding of the unit and the method of unit construction;（3）Junior high school chemistry teachers have recognized some requirements of the unit teaching design,but the implementation level needs to be improved urgently;（4）There are many factors that affect the teaching implementation of junior high school chemistry unit.Third,according to the previous theoretical research and exploration results,the goal is to construct three major concepts of "the nature and use of matter","the composition of matter",and "the change and transformation of matter".Determined and demonstrated the three unit themes of "Water and Solution","The Mystery of the Composition of Matter" and "Explore the Carbon Family",reconstructed the contents of the three units,and carried out the corresponding unit teaching design.The feasibility of the case was tested through questionnaires and interviews,and the unit teaching case was improved according to the revised opinions of the subjects.Finally,on the basis of theoretical and empirical research,three suggestions for promoting the unit teaching practice of big idea are put forward:（1）Encourage teachers to strengthen their own learning construction and take the initiative to learn the content of relevant unit teaching;（2）Set up a unit teaching team to promote the implementation of junior high school chemistry unit teaching;（3）It is hoped that the relevant education departments will carry out relevant training for front-line teachers in unit teaching based on big idea.