Research On The Cognitive Development Level Of Chemical Reaction Principles

The new curriculum standard advocates "literacy-based" teaching,and the connotation of chemistry core literacy not only includes the subject knowledge and thinking methods that students need to master,but also the key ability and essential character of students' future growth and development.Therefore,it is important to cultivate and implement students' core literacy from the overall perspective of knowledge development in the secondary school stage,and to carry out related research on teaching and practice based on this,but it is found that the cross-section holistic research on the development of knowledge and understanding related to complex decomposition reactions from the empirical perspective is very lacking."Compound decomposition reaction principle knowledge" involves many chemical reaction principles,is an important theoretical tool,according to the middle school chemistry curriculum structure design,its content presents the characteristics of mutual undertaking,continuous deepening,the perspective and depth of understanding from macroscopic qualitative to microscopic quantitative,from isolation to systematic dynamics of advanced cognitive development,both contains their own knowledge content learning characteristics and carries the functional characteristics of promoting the development of students' disciplinary thinking.On the basis of the research status of the review literature and the practical experience of teaching,this paper analyzes and deconstructs the knowledge of the principle of complex decomposition reaction in the middle school stage from the perspective of the whole,creatively proposes the knowledge understanding model of the principle of complex decomposition reaction in the middle school stage based on the deep development of the cognitive object,the cognitive angle and the level of understanding,and selects the students who have completed the knowledge of the principle of complex decomposition reaction in the middle school stage as the participants,and compiles a questionnaire to explore the current status of the cognitive development level of the students' knowledge of the principle of compound decomposition reaction.With the help of Rasch measurement theory and Winsteps software,the data extracted from the questionnaire was analyzed in a combination of qualitative and quantitative methods,and the results were as follows:(1)In the relevant indicators of the test tool,the scoring reliability(scale reliability)is 0.93,which has good internal consistency;the mean difficulty is 0.07,the resolution is 9.85,which has a certain difficulty performance and difficulty depth;in the one-dimensional test,75% of the items fall in the range of-0.4 to 0.4,which has a good test validity;The MNSQ values of the participants and projects are very close to the expected value of the MNSQ values of the Infit and Outfit1,and the ZSTD indicators of the overall Infit and Outfit are close to the expected value of0,which shows that the questions in the questionnaire fit well with the Rasch model and can achieve the purpose of measuring the cognitive level of students.(2)The total score of the assigned score and the number of responders of different codes are normally distributed,which is in line with the normal state of teaching and can reflect the real situation;Students' cognitive perspective focuses on macroscopic-micro-symbolic,tends to qualitatively decharacterize in curve representation,lacks quantitative thinking,and is accustomed to understanding the principle of complex decomposition reaction principle knowledge from a static-systematic perspective.According to the principle of compound decomposition reaction,the level of knowledge and cognition of students is at level 2,which can achieve the depth of macro-micro combination-preliminary quantitative understanding,which may be due to the fact that the teaching of the elective stage pays more attention to knowledge,emphasizes the systematic teaching of knowledge,and lacks a dynamic teaching perspective that promotes the development of knowledge.Based on the above research conclusions,the author believes that education researchers should combine teaching practice,cultivate students' dynamic cognitive perspective,use existing core concepts,and "one to one hundred" in teaching,from knowledge-based to literacy-based combination of knowledge and ability;The basic concept of chemistry is intrinsically related to the core literacy,and the basic concept of chemistry is highlighted in the teaching,and the multi-angle understanding method helps students to form the core literacy of the discipline;The chemical "quadruple characterization" ability based on mathematical thinking is more and more valued,and in teaching,attention should be paid to the cultivation of students' quantitative calculation ability and multiple representation ability,which is conducive to the development of students' understanding.