A Study On Electrolyte Aqueous Solution Model Cognitive Ability Of High School Students

Thinking with models is the way of thinking of scientists in research and exploration,and the modeling approach is an important method for research in chemistry and an important method for students to learn science.The new era curriculum reform requires science education not only to help students master scientific knowledge,but also to cultivate students' discipline core literacy in the process of promoting the formation of students' knowledge system.As a key ability in chemistry,model cognitive ability plays an important role in this process.Therefore,conducting research on the measurement of students' model cognitive ability is an important way to promote the development of students' core literacy,which is in line with the purpose of reform and development of chemistry education in the new era of China.Electrolyte aqueous solution are one of the core topics of high school Chemistry,and are also the key content of the entrance examination,throughout the study of chemistry in secondary schools.Through the analysis of curriculum standards and chemistry textbooks,it is easy to find that the content difficulty of electrolyte aqueous solution spirals throughout the high school level,and the learning of knowledge of electrolyte aqueous solution requires analyzing problems from macroscopic,microscopic and symbolic perspectives,and students can understand and master the characteristics of chemistry subjects only when they establish the connection between these three perspectives.Since the subject knowledge of electrolyte aqueous solution involves the understanding of the state of ions in aqueous solution from microscopic perspective,which is unobservable and complex.It requires students to construct models to understand and form the knowledge system of electrolyte aqueous solution,so it is important to use electrolyte aqueous solution as a theme to test students' model cognitive ability.In this study,the knowledge content of electrolyte aqueous solution was determined by combing the academic and content requirements in literature,textbooks and curriculum standards from three aspects: ionization(electrolyte),ionic reaction,and chemical equilibrium.On the basis of combing the achievements of model cognition at home and abroad,the electrolyte aqueous solution model cognitive ability evaluation framework was constructed based on Bloom 's taxonomy of educational objectives and Constructivist Learning Theory.In this framework,the electrolyte aqueous solution model cognitive ability was divided into four levels from low to high,and each level was described in detail.On this basis,the key points of examination were determined,and the electrolyte aqueous solution model cognitive ability assessment tool was developed.The assessment tool was optimized through the test.And the students of grade two and grade three in a municipal middle school and a county middle school in Shanxi Province were selected as samples.The questionnaire survey method and interview survey method were used to test.The Rasch model and SPSS statistical software were used to sort out and analyze the collected questionnaires.On the basis of confirming the good reliability and validity of the electrolyte aqueous solution model cognitive assessment tool,a comprehensive and systematic diagnosis of the overall electrolyte aqueous solution model cognitive performance of senior high school students,as well as the differences among students of different grades and schools was made.It provides a reference for teachers' teaching and a basis for the evaluation and research of chemistry discipline core literacy.The following conclusions were drawn from this study: 1)The high school students' electrolyte aqueous solution model cognitive ability evaluation index system consists of four levels: cognition,understanding,analysis and application;2)The assessment tool for high school students' electrolyte aqueous solution model cognitive ability which consists of 21 items,including blank filling,selection and brief answer.The process of pilot testing,interviews with front-line teachers,quality checks,and optimization showed that the revised assessment tool had good reliability and quality;3)The overall average level development of high school students ' electrolyte aqueous solution model cognitive is at level 2;4)There are significant differences in electrolyte aqueous solution model cognitive ability among different grades and schools.