Case Study Of High School Chemistry Experience Teachers In The Perspective Of PCK

The promulgation and implementation of the General Senior High School Chemistry Curriculum Standards(2017 version)puts higher demands on teachers.Chemistry teachers must keep up with the pace of the new curriculum reform and realize their own professional development.The pedagogical content knowledge(PCK)is the necessary knowledge for the professional development of teachers.It is the bridge knowledge that teachers adapt to the new curriculum standards and change the teaching concept and teaching behavior.Therefore,it is necessary to deeply explore the PCK characteristics of teachers.The main purpose of this study is to better understand the PCK characteristics of teachers in different types of chemical content.Therefore,using the case study method,two empirical teachers from a key middle school in a certain city of Shanxi Province were selected as research objects.Different types of chemical content,namely chemical concept and chemical facts,are the subject of research;research is carried out from the five elements of PCK,namely,teaching target knowledge,student knowledge,teaching strategy knowledge,evaluation knowledge and reflective knowledge.By using classroom observation method,text analysis method and interview method to collect data,and sorting and summarizing,the PCK characteristics of two types of empirical chemistry teachers in different types of chemical content are obtained.The results of the study show that,overall,the two teachers have significantly different PCK characteristics in the teaching of these two types of chemical content.(1)In terms of teaching objectives,the two teachers focus on the understanding of the essence of the concept and the mastery of basic skills in the teaching of chemical concept knowledge,and pay attention to the core concepts of infiltration of chemistry,and cultivate students' "modelcognition and concept construction." The core literacy;in the teaching of chemical facts,it not only focuses on the understanding and memory of knowledge,but also on the cultivation of students' core concepts of chemistry,disciplinary thinking and core literacy.(2)In terms of student knowledge,the two teachers in the teaching of chemical concept knowledge show that the existing knowledge comes from the content learned in the previous classroom,the difficult knowledge stems from the abstraction of the concept,and the misunderstanding appears in the concept understanding and application.In the knowledge of chemical facts,the existing knowledge comes from life experience and junior high school.The knowledge of both difficult and wrong is derived from the special nature of the elements and the memory of the equation.(3)In terms of teaching strategy knowledge,the two teachers used the teaching strategies of consolidation,triggering cognition,macro-characteristic triple representation,and inductive deduction in the teaching process of conceptual knowledge;knowledge of chemical facts In teaching,the use of analog learning,combined with life practice,contact existing knowledge,experimental inquiry,knowledge structure,association with unknown prediction and model construction teaching strategies.(4)In the aspect of evaluation knowledge,the evaluation of chemical concept knowledge teaching is mainly the evaluation of students' ability to master the situation,and it is generally based on formative evaluation,supplemented by diagnostic evaluation;in the evaluation of chemical facts knowledge teaching,mainly It is an evaluation of students' memory and ability,and it is mainly a formative evaluation,and there are few diagnostic evaluations.(5)In the aspect of reflective knowledge,in the teaching of chemical concept knowledge,the teacher's teaching reflection is mainly based on reflection in the class,focusing on the regulation and reflection in teaching;in the teaching of chemical facts,the main reflection is after class.Lord,pay attention to the evaluation after the teaching.In this regard,the following suggestions are made for teachers to upgrade their PCK:formulating the "scientific-based" teaching objectives;constructing a "thematic" teaching strategy library;conducting "all-round" teaching reflection;using "real-time" teaching evaluation,thus effectively Promote your own PCK and promote the professional growth of teachers.