The PCK Comparative Study Of High School Chemistry Teachers On "Material Structure And Properties"

Pedagogical Content Knowledge(PCK)is the knowledge that teachers use their own knowledge to help students learn and understand the content of a specific subject.It is an effective combination of subject knowledge and pedagogical knowledge and plays an important role in the professional development of teachers.Based on the different types of high school chemistry teachers in "material structure and properties " under the theme of PCK comparison,found that novice teachers,proficient teachers and expert teachers in the subject of PCK under different,and targeted to the novice teachers and proficient teachers put forward the corresponding suggestion,promote their faster to proficient teachers and expert teachers development.Through reading the literature,this paper clarifies the characteristics of novice teachers,proficient teachers and expert teachers,understands the relevant course contents of "material structure and properties" and the relevant teaching strategies in the existing research,clarifies the connotation and composition elements of PCK,understands the relevant research of different types of teachers PCK and the method of surveying PCK,and on this basis determines the structure framework of PCK.This paper adopts classroom observation method,text analysis method and interview method to conduct case study on a selected novice teacher,a proficient teacher and an expert teacher from four aspects: teaching knowledge,knowledge of students,subject knowledge and curricular knowledge.It is found that the novice teacher can use the multimedia technology to characterize the chemical knowledge and evaluate the students in many ways,but the teaching strategy is single,which neglects the main position of the students in the teaching.The novice teacher is not rich in the knowledge of students.She has sufficient theoretical knowledge and lacks of practical experience,but she has consciously accumulated the knowledge of students in the course of daily teaching.In subject knowledge,she can correctly understand the characteristics of the subject of "material structure and properties",but she is not familiar with the basic knowledge of chemistry.In terms of curricular knowledge,she can correctly understand the curriculum objectives of the "material structure and pro-perties" module,but the expression of teaching objectives is not reasonable enough.The proficient teacher and expert teacher have great differences in the accumulation of the knowledge of students and the understanding of literacy goals in curricular knowledge.The proficient teacher pays less attention to the influence of students' own characteristics and existing knowledge base on students' different ideas,and the expert teacher can make correct attribution analysis on the causes of students' different ideas.The development of students' core accomplishment is less considered by the proficient teacher when setting the teaching goal.The knowledge of expert teacher in all aspects is relatively rich,but in teaching knowledge,less use of multimedia technology to characterize the knowledge,also does not reflect the evaluation of students' literacy.On the basis of the analysis results,this paper puts forward corresponding suggestions to novice teachers,proficient teachers and expert teachers: novice teachers should do more exercises,look through the teaching materials,be familiar with the basic knowledge of chemistry,pay more attention to the students' state in class,pay more attention to the students' main body position,and apply the theoretical teaching strategies to practice more.Proficient teachers should communicate more with students,accumulate the knowledge of stuednts,and improve their understanding of students' literacy goals by reading periodicals of chemistry education.Expert teachers should think more about developing methods to evaluate students' literacy.Put forward corresponding teaching suggestions for the selected lesson examples: Connect new knowledge with existing knowledge.Students are encouraged to understand the rules for the arrangement of extranuclear electrons in the ground state atom by writing the rules for the schematic diagram of the atomic structure.Then,by studying the arrangement of electrons outside the nucleus in a more detailed way,we can understand the reasons for writing the rules for the schematic diagram of the atomic structur.So that students not only "know",but also "know why".Provide data to students and organize students to draw the trend chart of the first ionization energy.Students can find out the rules themselves and think about the reasons.In this way,students are trained to use evidence for reasoning.