Research On Curriculum Development To Promote The Development Of Pre-service Chemistry Teachers' Subject Teaching Knowledge

The core intellectual task of teachers' teaching is to transform the subject content knowledge into a form that students can easily understand.To complete this task,teachers must have a lot of pedagogical content knowledge(PCK).PCK is an important knowledge base for teachers' professional development.As a key stage of teachers'professional development,pre-service education plays a very important role in the formation and development of teachers' PCK.PCK model is the ideological basis and goal direction of teacher's PCK development.It is of great significance to construct pre-service teacher's PCK model.Compared with the mature PCK model of in-service teachers,the PCK model of pre-service teachers is rarely reported.Based on this,this study constructs a PCK model for pre-service chemistry teachers,defines the core elements and specific components of pre-service chemistry teachers' PCK,and develops a "PCK curriculum" to promote the development of pre-service chemistry teachers'PCK under the existing teacher education framework,and empirically tests the effectiveness of the "PCK curriculum".This study mainly includes the following four aspects:Firstly,the construction of PCK model for pre-service chemistry teachers.On the basis of Shulman's definition of PCK,Grossman's knowledge structure theory and Magnusson's PCK model,this study identified the core elements and specific components of pre-service chemistry teachers' PCK,and constructed a "localized"pre-service chemistry teacher' PCK model through literature analysis,expert interviews and rational analysis.The model includes four core elements and seventeen specific components.The element of Orientation of Teaching Science includes two components,namely,the philosophy of science teaching and the characteristics of science teaching.The element of Knowledge of Science Curriculum includes seven components,such as discipline key competency and curriculum objectives,etc..The element of Knowledge of Students' Understanding in Science includes five components,such as the prerequisite knowledge for learning a specific topic,etc..The element of Knowledge of Instructional Strategies and Representations includes three components,such as the general approaches to enacting science instruction,etc..By the method of grouping and differentiation and exploratory factor analysis,the results showed that the validity of PCK total scale and PCK elements sub-scale based on the model were very good,which showed that the model was scientific.The model provides a theoretical basis for the subsequent development of "PCK curriculum".Secondly,the design of "PCK curriculum".Under the guidance of PCK model.Taylor's principle and Bernstein's integrated curriculum theory,this study designed a"PCK curriculum" based on the existing teacher education framework through literature analysis and rational analysis.According to the essential and inevitable relationship between teaching skills and PCK and its development,this study chose to design "PCK curriculum" relying on the course "chemical instructional design and micro-teaching".Then,based on the four elements and seventeen components contained in the PCK model of pre-service chemistry teachers,and taking the PCK of a specific subject as the development object,the curriculum objectives of "PCK curriculum" are constructed from four aspects:understanding of basic knowledge,collection and accumulation of specific component knowledge of four elements,processing and integration of specific component knowledge of four element.and transfer of the learning methods about topic PCK.Finally,based on the actual situation of PCK achievements,this study selected and organized the content of "PCK curriculum" in the "integrated curriculum",framework under the guidance of Taylor's basic theory of "two types" and "three criteria" about curriculum content.Thirdly,the implementation of "PCK curriculum".Teaching is the main way of curriculum implementation.The implementation of "PCK curriculum" in this study is essentially the teaching of "PCK curriculum".First of all,on the basis of nature of PCK.the objectives and contents of "PCK curriculum",the knowledge construction theory of Rumelhart and Norman,and the development experience at home and abroad,the implementation strategies of "PCK curriculum" were designed,including "five kinds of learning","three kinds of practice" and "two discussions".The activities of "five kinds of learning",namely,learning based on textbooks,curriculum documents,journal literature,teaching videos,and recalling and investigating,aim to promote the independent development of the four elements of pre-service chemistry teachers" PCK,and complete the the curriculum objectives related to "collection and accumulation of specific component knowledge of four elements".The activities of "three types of practice",that is to design teaching plan,record teaching video and transcribe self teaching video,aim to promote the integration of the four elements of pre-service chemistry teachers' PCK,and complete the curriculum objectives related to "processing and integration of specific component knowledge of four elements".In the activities of"two seminars",the activity of "report and exchange seminar" aims to promote the expansion of the four elements of PCK for pre-service chemistry teachers,and the activity of "reflection and evaluation discussion" aims to promote the fourth integration of the four elements of PCK and the overall expansion of pre-service chemistry teachers' PCK.The activities of "two seminars" jointly complete the the curriculum objectives related to "transfer of the learning methods about topic PCK".Then,by means of purposive sampling method,56 pre-service chemistry teachers with solid subject knowledge and general pedagogical knowledge were selected as the implementation objects,and the "PCK curriculum" was organized and implemented in three stages of "preliminary preparation","independent development" and "integrated development".Fourthly,the evaluation of "PCK curriculum" and its corresponding implementation strategies.All of these factors,including naturalism position,PCK characteristics,similar research experience at home and abroad,and the purpose of describing deeply the development and change process of pre-service chemistry teachers' PCK,made this study choose the "qualitative evaluation method based on case study" finally.Among all the 56 pre-service chemistry teachers who participated in the curriculum implementation research,a pre-service chemistry teacher was selected as the object of evaluation study by using purposeful random sampling methods twice.The evaluation data were collected by semi-structured interviews,simulated teaching video,document collection and other methods,and the data were analyzed by using in-depth analysis of explicit PCK,PCK maps and continuous comparison methods.The results show that the "PCK curriculum" and its corresponding implementation strategies are effective both in terms of the development of pre-service chemistry teachers' PCK and the achievement of the objectives of the "PCK curriculum".After the completion of the core research content,this study also tried to put forward the development model of pre-service chemistry teachers' PCK based on the"PCK curriculum" and some views on the integration essence of PCK elements through in-depth mining and detailed description of the development process of case teacher's PCK.In the end,the paper also looks forward to the future.