Principal Component Analysis And Its Application Of Factors Affecting The Difficulty Of Chemical Items In College Entrance Examination

Item difficulty is one of the evaluation indicators of the quality of college entrance examination.An all-round study of factors affecting the item difficulty is the basis for ensuring difficulty in a reasonable scope and an important part of scientific proposition.We find out the factors that affect the difficulty of chemical items in College Entrance Examination through literature analysis,and then reveal the relationship between these factors by using principal component analysis.The problem-solving behavior chart of students are established through interviews to further explain the results of principal component analysis.Finally,we try to analyze the causes of students' problem-solving errors by using problem-solving behavior charts,and then give some enlightenment to propositions and teaching.The conclusions of this study are as follows:(1)The factors that affect the difficulty of chemical items in College Entrance Examination include: the presentation of item information,the number of information provided by item,the interaction of information provided,the proficiency of test situation,contents of multidisciplinary,the comprehensive application of knowledge,the complexity of knowledge,the thinking level of test required,the speculation of answer,the presentation of answer.(2)Three main components are extracted through the principal component analysis.The first one is the factor of item situation which includes the presentation of item information,the number of information provided by item,the interaction of information provided and the proficiency of test situation.The second component is the factor of problem-solving process including the comprehensive application of knowledge and the thinking level of test required.The third one is the factor of results presentation including contents of multidisciplinary,the complexity of knowledge,the speculation of answer and the presentation of answer.(3)With the interview of students on problem-solving and the guidance of some related theories,it is revealed that students will undergo three stages when solving problems which correspond to the three factors.The factor of item situation mainly affects the process of problem representation,the factor of problem-solving process influences the process of information searching and the factor of results presentation mainly acts on the process of results presentation.Thus we can construct the problem-solving behavior chart.(4)We can analyze the causes of students' problem-solving errors by using problem-solving behavior chart,diagnose students' thinking level,then give someenlightenment to teaching and the College Entrance Examination proposition in the background of new round curriculum reform.