Cognitive Differences Of Junior Middle School Students In The Process Of Solving Mechanical Problems With Different Difficulties

Students' ability to solve scientific problems is an important embodiment of their scientific literacy.In the process of solving different difficult mechanical problems,eye tracking technology reflects the process of instant cognition in the process of scientific problem solving at a certain level.Through eye movement analysis,the study achieve the following results: first,in the process of students correctly solving problems with different level of difficulty,as the difficulty of problem increases,total fixation duration,total number of fixation,total number of regression,fixation duration on key information,the number of fixation on key information,the number of regression on key information significantly increase.Second,significant differences of the students' eye movements indicators reveal with different problem-solving behavior.On one hand,when solving difficult problems,total fixation duration,total number of fixation,total number of regression of the correct problem solvers are significantly less than those erroneous problem solvers,while fixation duration on key information,the number of fixation on key information,the number of regression on key information of the correct problem solvers are significantly more those erroneous problem solvers.When solving the simple problem,there is no significant difference in the eye movement indicators of the correct problem solvers and erroneous problem solvers.On the other hand,eye movements indicators of students with different problem-solving speed also reveal significant differences.Compared with slow problem solvers,total fixation duration,total number of fixation,total number of regression of quick problem solvers significantly reduce,while fixation duration on key information,the number of fixation on key information,the number of regression on key information significantly increase.Besides,fixation duration on key information,the number of fixation on key information,the number of regression on key information of quick problem solvers are significant more than fixation duration on non-key information,the number of fixation on non-key information,the number of regression on non-key information,while the difference of eye movement indicators of slow problem solvers in these two kinds of information is not significant.Third,in the process of problem solving,there is asignificant difference in the eye movement indicators of the students of different grades.In solving simple problems,total number of fixation and regression,as well as the number of fixation and regression on key information of nine grade are significantly more than those of eight grade students;difference of the number of fixation and regression,and fixation duration of nine grade students on key information and non-key information is significant,while difference of eight grade students is not significant.In solving the difficult problems,there is no significant difference in the eye movement indicators of the students of different grades.The results show that students' cognitive load will increase as the difficulty of the problem increases.In the process of problem solving process,the quick and correct problem-solving students have a wealth of knowledge in the relevant field,and they can flexibly use knowledge to solve problems,while wrong problem-solving students whose knowledge is relatively independent,so it is difficult for them to coordinate the related knowledge to solve problems.Compared with the eight grade students,the nine grade students have a lot of knowledge about the problem and can use their knowledge to solve the problem flexibly.