Probe Into The Mystery Concept Of "Solution" In Junior High School Chemistry And Research On Its Effective Transformation Strategy

This paper first analyzes the misconceptions and its causes of junior high school students before learning "solution" through "pre-test".Through extensive literature,we find a more effective conceptual transformation teaching model,and select appropriate classes as experimental and control classes.Teaching,through the "post-test" to compare the teaching effects of the two classes,to test the effectiveness of the concept teaching model,aiming to explore a scientific and efficient concept transformation strategy for the first-line junior high school teachers.The specific research contents are as follows:The first stage: explore the misconceptions of the third-year students before learning "solution".Based on the feedback from peers and the frequent mistakes of previous students on “solutions”,the author prepares a pre-test questionnaire with good faith and validity,and uses a cluster sampling method to interview 306 junior high school students in a junior high school in Yucheng Street,Zengcheng District before learning "solution".After multi-dimensional and meticulous analysis of the data obtained from the pre-test,it is found that there are many typical misconceptions before the students learn the "solution",especially regarding "saturated solution","crystallization","emulsification","solution preparation".The second stage: the implementation of experimental teaching,verify the teaching effect of the concept transformation strategy of PDEODE(PredictionDiscussion-Explanation-Observation-Discussion-Explanation).The teaching practice part of this paper adopts comparative experiment teaching.The experimental class and the control class are taught by the same teacher and are all parallel classes.The students have the same level of study.Teachers use the concept of PDEODE to change the teaching strategy in the experimental class,while the control class adopts the POE teaching strategy that is close to the traditional teaching method of chemistry.The author uses the key concept of “solution” as the basis for conducting comparative teaching,and designs different teaching processes under the PDEODE and POE teaching strategies,so that the two chemistry teachers who participated in this experimental teaching will practice together and do the same in the case of natural teaching.It is possible to control the interference of unrelated variables,making the feedback of results under different teaching strategies more convincing.The third stage: after the contrast teaching,prepare a post-test questionnaire with the concept of “solution” as the examination content and good reliability and validity.For 3 experimental classes(101 people)and 3 control classes(105)A total of 206 students were tested After detailed statistical analysis,it was found that the misconceptions discovered in the pre-test was mostly changed to the scientific concept after learning,especially the effect of the experimental class was much more significant than that of the control class.Therefore,this paper concludes that the concept transformation strategy of PDEODE is of practical significance and is worthy of adoption by the junior chemistry teachers.Since the implementation of the PDEODE concept transformation strategy should generally be based on experiments,and it is necessary to first study the misconceptions in the minds of students before the concept through pre-test analysis,in order to propose targeted problems in the "predictive" link to guide students to discuss and explain.In order to promote this strategy on a larger scale without giving the teacher too much workload,this article gives some advice to frontline teachers:(1)In the concept change teaching,experiment should be used as the medium as much as possible,and the experimental content should be integrated to facilitate students to construct relevant concepts into the scientific cognitive system through "Discussion" and "Explanation" in the experiment process.(2)Group cooperation should be emphasized in the concept change teaching.Students can unload their defenses among their peers,and can fully expose misconceptions in "Discussion " and "Explanation",so as to facilitate the revision and construction of related concepts in the process of subsequent exploration.(3)Before the concept change teaching,the pre-study case should be designed to explore the misconceptions of the students who are about to learn.It is easier to explore the content of the investigation in the first few questions of the study preparation,and at the same time,it can adjust the teaching strategy in time.