Research On The Difficulty Prediction Of High School Chemistry Textbook

《The basic education curriculum reform just wanted to》 put forward to change the present situation of course content is "difficult, complex, partial, old" and obsessed with the book knowledge. Textbook exercises after class as an important way to consolidate knowledge, it’s difficulty also should be controlled in the appropriate range. Just do this, the textbook can both achieve the teaching goal and keep up with the pace of the curriculum reform. Item difficulty is an important index for evaluating items, to grasp the item difficulty is the key to improve the quality of textbooks and homework in the process of topic selection and proposition. But in the context of the current literature, study of textbook exercises’ difficulty after class is very few. This makes losing an important basis in the selection of homework problems for writing textbooks. If we can know the difficulty of the exercises before selecting them by some sort of tool or method, that can be more objective to add appropriate exercises in the writing teaching material. This is not only in favor of improving the quality of the teaching materials, but also more advantageous for students to grasp the knowledge. In view of this, this study has carried on the related research on high school chemistry textbook exercises after class.This study firstly proposed14factors influencing exercises difficult assumption that based on the study of many relevant literatures on, they are learned number, additional knowledge points number, practice goal level, problem representation, distractions, item background, the length of the title, the number of material’s information, operation requirements, problem solving skills, reasoning number, question types, the degree of familiar with and the difficult degree of information recognition. On this basis, that various factors were carried on the investigation and study in students by way of questionnaire survey, the result display that13factors were considered can impact item difficulty without the’"item background".Then, this study adopts the method of quantitative value assignment and statistical analysis analyzes the14factors from the actual situation to solve the problem. The first step is to set the factors of quantitative valuation standard; Second, select an item to examine the reliability of that quantitative standards set; Third, choose exercises after class to get the actual difficulty, and analyze problem sets according to the above quantitative valuation standard, then get assignment number of each factor; The last step, using analysis software for statistical analysis based on the results of the above analysis, finally getting that the factors of affecting the item difficulty are additional knowledge points number, learned number, item background, practice goal level, reasoning number and reasoning number.Finally, the prediction model of high school chemistry textbook item difficulty was established after determining the influencing factors. And got a regression equation that marked the measured difficulty as the dependent variable (marked as y) and six influencing factors as the independent variable (marked as x1, x2,...,x6). After achieving the number of various factors, bringing it to the above equation and the y value is the forecasted difficulty. Through inspection, problem sets are obtained by the model and equation of estimated difficulty value, to a certain extent, can better response problem of the measured value is difficult. And this forecast model and regression equation is effectiveness after experimental verification.