The Application Research Of Rasch Model In Chemical Concept Teaching

An irreplaceable component in the chemical knowledge system is the chemical concept,and the teaching of chemical concept is increasingly scientific.The redox is an important concept,according to the literature,the research on the teaching of redox mainly includes the study of teaching method,design of teaching cases,and the recognition of redox.There are few research on the student's mastery of the redox,and the method used in the domestic and foreign literature on the concept of measuring students' redox are difficult to use for first-line teachers.Based on the Rasch model,this paper explores the understanding of the concept of oxidation-reduction in senior school students,and uses Conquest and Winsteps to analyze students' test scores,aiming at providing a simple and feasible method for first-line teachers to test students' concepts.The conclusions of the study are as follows:(1)Using the Rasch model to detect the quality of the test.The InfitMNSQ and OutfitMNSQ values of the 15 test items in the test are all in the range of 0.5 to 1.5,and the ZSTD values are in the range of-2 to 2,which means that the students' actual test scores fit well with the model's expected estimates.The value of the separation reliability of the test is 0.98,indicating that the test volume has high reliability and strong separation.The standard error of item 15 in this test is relatively large.According to White's chart,test subjects with different levels of difficulty have students with corresponding levels.According to the standard residual graph,the questions 2 and 11 in the test don't detect the single trait structure of the student.(2)The analysis of students' scores.Based on the Rasch model,the effectiveness of student' test scores was analyzed.According to the results,the test scores of students numbered 7 and 21 differed significantly from the model's expected estimate.According to the white chart,it can be seen that the ability of students is higher than the difficulty level of this test.According to the analysis of students' answers to each question,most students can correctly understand the concept of redox and apply it,but the students' application of redox law is not ideal.