Research On The Development Of Junior High School Students' Ability To Control Variables

The scientific inquiry ability of middle school students plays an important role in the process of personal cognitive development and the future social work.To achieve the expected results of inquiry,one must master the ability to handle the relationships between variables in inquiry activities,that is,the ability to control variables.Through the review of literature and texts,the author interviews front-line teachers and divides junior high school students' ability to control variables into four sub-abilities:variable identification,experimental hypothesis and design,operation and judgment,analysis and reasoning.According to their performance,we divide them into different levels,then construct junior middle school students' ability framework of control variables.Based on the framework of the control of variables ability,the author developed the "Junior Student Control Variables Ability Test Tasks" which contains three inquiry tasks by conducting interviews with front-line teachers and discussing with experts.After pre-test,the test results were analyzed by Winsteps3.72.3 software of Rasch model.Based on the analysis results,the test task was revised,and the modified test task was used in the empirical study of junior high school students'ability to control variables.The author selected two junior high schools which from the surrounding townships of Xi'an and the main city of Xi'an.Randomly select three classes in each school as the sample of the research.The test data were qualitatively and quantitatively analyzed by Winsteps3.72.3 software.Firstly,we use Winsteps3.72.3 software for separation and single-dimensional and other overall statistical analysis of large samples.In the case of the test tool has good performance indicators and Rasch model can fit well,we conducted a detailed analysis of the student's control variable MEASURE values and compared the control variable capabilities of different sample groups.In addition,through the study of the development balance of the each sub-ability of control variable,the key development period of the each sub-ability is determined.The comparison of the ability of control variables among different sample groups is mainly carried out in the following three aspects:? comparison of advanced levels of student control variables in different grades;? comparison of student control ability levels in different schools;?comparison of the ability levels of control variables in different genders.The analysis found that there was a significant difference in mean MEASURE value among students in different grades.The grade three of junior high school students was better than grade two,and grade two was better than grade one.There was no significant difference in the ability of control variables between the two schools.There was a significant difference in mean MEASURE values between the control variables of boys and girls,and girls had better control variables ability than boys.The development balance of control variable sub-ability studies shows that as the grade increases,the overall control variable capacity of junior high school students shows an increasing trend.Among them,the grade one to grade two are the critical period for the development of experimental hypothesis and design sub-ability,and the grade two to grade three is the critical period for the development of variable identification,operation and judgment,and analysis and inference sub-ability.The research results show that junior high school students already have some ability to control variables in the process of scientific inquiry.Some students have been able to design controlled experiments to verify the hypotheses and can reason based on the existing data.Based on this,schools and teachers should actively carry out educational research to promote the development of relevant abilities of junior high school students.At the same time,the author explores the issues that need to be further studied based on the insufficiency of some studies,in hope that it can provide some reference for advanced researchers and front-line teachers.