Development And Application Of The Evaluation Instrument Of Chemistry Textbook Learning Difficulty

Academic overburden of primary and middle school students has been the focus of attention of the public for years, and the curriculum difficulty has been considered one of the important reasons. Considering that curriculum difficulty is a reflection of the national education level and affects the education competition, how to scientifically evaluate the curriculum difficulty to eliminate unreasonable factors and alleviate academic burden becomes the urgent question that current curriculum reform must answer. As the carrier of curriculum and the most important learning resources, textbook embodies the difficulty of the courses and greatly affects students’learning methods and quality, thus research of the textbook learning difficulty becomes the only way to solve the above problem.From the readability to the comprehensibility and acceptability and finally focused on the learnability of curriculum and textbook difficulty, people has been constantly looking for the textbook characteristics which result in learning difficulties, and developed numerous difficulty assessment tools for this purpose. But because the factors which affect the difficulty of textbooks are so many and complicated, the assessment tools have various limitations, and the research methods have some shortcomings, that the evaluation of science textbook learning difficulty still lacks scientific and effective means until now, thus greatly influenced the science curriculum evaluation and textbook quality enhancement. Based on these practical problems needs to be solved, this study is focused on the middle school chemistry curriculum and conducted the instrument development and application of the chemistry textbook learning difficulty evaluation, which is divided into five chapters as follows.In the first chapter, after the definition of the core concept and review of literature about the history and evaluation methods of textbook difficulty at home and abroad, the research determined the study paths and objectives as follows:followed the dynamic and static orientation, the research conducted comprehensive exploration of the factors that influence chemistry textbook learning difficulty, and clarified their relationships;on this basis, integrated various methods to establish a systematic assessment framework, then applied it in international comparison.In the second chapter, based on the analysis of chemistry textbook structure and characteristics, both the literature and investigation study were conducted, from the study result the main factors that affecting the learning difficulty of chemistry textbook were extracted. They were relevant to the content, organization, and characterization of textbook,such as "difficulty of content breadth","difficulty of content depth""difficulty of content quantitative degree","difficulty of organizational logic","difficulty of organization leading","difficulty of text characterization","difficulty of image characterization" and "difficulty of text-image characterization"In Chapter three and Chapter four, evaluation indicators at all levels has been gradually established by the following steps:connotation analysis on influencing factors, content validity index selection, standards development and reliability test.Such process ensured the effectiveness, operability and reliability of the evaluation indicators. Finally, expert consulting method and Analytic Hierarchy Process (AHP) were applied to the assigned weights of indicators at all levels, and the student and teacher evaluation criterion was adopted to demonstrate the user validity of the index system.In the fifth chapter, the evaluation instrument was applied to assess the difficulty in "chemical reaction rate and chemical equilibrium" theme of textbooks from five countries. The evaluation results revealed the differences between china and other countries in middle school chemistry curriculum difficulty from micro and whole aspects and further confirmed the scientificity and validity of the evaluation instrument.Following the main line of extraction of learning difficulty factors, development of assessment instrument, and testing and application of the instrument, this study formed a set of complete and operational methodology system and explored the international trend of chemistry textbook compilation, the similarity and differences between china and other countries on important theme in middle school chemistry textbooks, thus the current study not only has theoretical and practical significance, but also methodological meaning. However, in the vast field of textbook learning difficulty research, this study is just a start, not only the evaluation instrument should accept practical test and revision, its application also needs to be further developed, such as the individual difference of adaptive research, the overall continuity research and comparative study based on a more broad international vision, etc.