Middle School Chemistry Teaching Design And Implementation Based On NGSS Science And Engineering Practice Concept

The development of science curriculum standards determines the quality of science education.The Next Generation Science Standards(NGSS)consists of three dimensions: core concepts,science and engineering practices,and interdisciplinary concepts.Among them,science and engineering practice is the most direct performance of practicalness.The practical implementation steps and implementation rules are presented in the form of practical elements.Teaching based on practical elements increases the scientificity and operability of practice.Chemistry is an inquiring science course.Scientific inquiry and practical literacy are undoubtedly an important aspect of chemistry curriculum standards.However,the clarification of the scientific inquiry in China's chemistry curriculum standards is theoretically strong,and there is no clear description of the implementation rules in terms of specific operations.Therefore,in terms of instructing teachers to carry out scientific practice teaching and cultivating scientific literacy,the operability and flexibility of China's chemistry curriculum standards are not strong.In order to promote the implementation of scientific practice and realize the cultivation of students' scientific literacy,this research focuses on the science and engineering practice part of NGSS.discusses and analyzes it,summarizes its basic theoretical content,analyzes the implementation characteristics,and draws the teaching design strategy.Develop teaching cases and conduct teaching practices.The research path of this paper is as follows: First of all,through the collation and analysis of the current research literature on NGSS at home and abroad,grasp the content and theoretical basis of NGSS science and engineering practice;Then,based on the concept definition,key elements and general principles of science and engineering practice,the implementation characteristics of the NGSS science and practice framework are obtained through case study analysis;Then,summarize its teaching design strategy and apply the strategy to exploit chemistry teaching design cases based on the theoretical basis and implementation characteristics of NGSS science and engineering practice;Finally,implementing and evaluating the teaching design case based on the NGSS science and engineering practice concept is in the classroom teaching and the practical effect through the action research method.The conclusions and innovations of the research are mainly reflected in the following aspects:First,the hierarchical structure of NGSS science and engineering practice is reviewed.The implementation of science and engineering practice includes eight practical steps.Among them,"constructing,developing and using models" is the purpose and core of scientific practice,and "participation in evidence argumentation" is the means of inquiry throughout the entire scientific practice process.And “propose questions”,“plan and implement surveys”,“analyze and interpret data”,“use mathematics and computational thinking”,and “acquire,evaluate,and exchange information” as a means of drawing and collating evidence.Then,the implementation characteristics of NGSS science and engineering practice are summarized.The implementation features are: to build a model or interpretation of the phenomenon as a teaching goal;Pay attention to the gradual progress of teaching,gradually improve the level of learning chemistry and inquiry;flexibly implement scientific practice,no longer model;clarify the key elements of science and engineering practice,and provide specific operational standards for teaching.Then,the teaching design strategy based on NGSS science and engineering practice concept was obtained.Strategies include both the selection and design of practical tasks.The selection strategies of practical tasks are as follows: select practical tasks with progressive difficulty;select practical tasks with integration;select practical tasks based on real situations.The design strategies of practical tasks are as follows: constructing interpretations for practical purposes;step by step as practical principles;using practice frameworks as operational standards;Simple and feasible is a prerequisite for practice.Finally,the advantages of teaching based on NGSS science and engineering practice concepts are verified.Through teaching experiments,this study tests the teaching effects from a qualitative and quantitative perspective.After the implementation and evaluation of teaching,the advantages of teaching based on NGSS science and engineering practice concept are as follows: Teaching based on NGSS science and engineering practice concepts have more practical activities and higher student participation;It can better help students to establish chemical concepts and improve their core literacy.It can promote students' knowledge understanding deeper and more comprehensive.