Research On The Evaluation Of High School Students' Cognitive Ability Of Chemical Model

Model cognition is an important part of the core literacy of chemistry discipline and an important thinking method to solve scientific problems.Therefore,developing students’ model cognition ability is an important way to cultivate innovative scientific and technological talents in the future.Most of the existing studies discuss how to cultivate students’ model cognitive ability from two aspects: theoretical construction and teaching practice,but there are few evidence-based studies on the evaluation of model cognitive ability.Based on this background,the main purpose of this paper is to quantitatively evaluate students’ model cognitive ability and qualitatively understand students’ real thoughts on the model,in order to provide reference for front-line teachers to diagnose and cultivate students’ model cognitive ability.This study is mainly divided into three parts.The first part combs the connotation,classification and function of the model,summarizes the teaching modes and strategies related to the chemical model,and further summarizes the related research on model evaluation.The second part,the development of model cognitive ability assessment tools.Based on the existing literature,on the one hand,chemical models are divided into three categories from the perspective of essential characteristics of knowledge,and on the other hand,an evaluation system of model cognitive ability with six dimensions is obtained by integrating curriculum standards and Bloom’s goal taxonomy.On this basis,the 3×6 framework system of model cognition is determined,that is,the embodiment of three types of chemical models in six dimensions of model cognition.Based on this framework system,the questionnaire tool is formed by screening questions.After preliminary test,it has good reliability and discrimination,and the difficulty is appropriate.The third part carries out quantitative evaluation and qualitative research.Taking 380 senior three students from Tianjin,Hainan and Hebei as the research objects,this paper makes a quantitative evaluation.At the same time,this study also interviewed 16 students around their understanding of the concept,function and essence of the model,and coded the collected qualitative data with grounded theory to draw the final conclusion.Based on the above questionnaire data and interview data,the conclusion of this study includes the following two aspects.The findings of quantitative evaluation are as follows:(1)On the whole,students’ model cognitive ability is low,and the number of students at the lower-middle level is the highest;(2)From all dimensions of model cognition,students’ ability to recognize models is the highest,while their ability to evaluate and construct models is the lowest,and the cognitive ability of higher-order models needs further development;(3)There is no significant gender difference in the cognitive ability of senior high school students.The findings of qualitative interviews are as follows:(1)The concept of model: most students think that model is a presentation form,aiming at explaining chemical concepts or mechanisms,but they only pay attention to the presentation in physical form,ignoring the presentation in symbolic form,and there are also some shortcomings in their understanding of theoretical models;(2)Understanding the function of the model: Most students think that the main function of the model is to promote understanding,and that the visualization of tiny material structures is the main means to promote understanding,but they ignore the visualization of abstract principles and laws by the model,and they don’t know much about how the model can promote the development of scientific research;(3)Understanding of the essence of the model:Most students have a dynamic view of model understanding,can recognize the limitations of existing models,and can point out that there may be multiple models for the same thing,but students’ awareness of creative use of models is still lacking.To sum up,this study adopts the methodology of combining quantitative evaluation with qualitative interview,which not only diagnoses the cognitive ability level of senior high school students at this stage,but also deeply explores their views on the model.Based on the existing conclusions,middle school front-line teachers should focus on improving students’ cognitive ability of higher-order dimension model in teaching practice,and finally promote the development of core literacy of chemistry.