Advanced Research On Chemical Change Learning Based On ChemQuery Evaluation System

The research on learning progressions is an important topic in the field of international science education in the last decade, which promotes the development of science education research methods. Just lots of studies have shown that the effective learning progressions for the big ideas are a critical path which promotes students’ scientific literacy. NRC(2007) defined learning progressions as “descriptions of the successively more sophisticated ways of thinking about a topic that can follow one another as children learn about and investigate a topic over a broad span of time.” The tyical development models include BEAR,CCD and ChemQuery. The ChemQuery assessment system is based on chemistry subject. ChemQuery is an assessment system that uses a framework of the key ideas in chemistry subject and criterion-referenced analysis using item response theory(IRT) to map student progress. The purpose of this research is to investigate and characterize how students learn the big idea of Chemistry Change from pre-instruction to deeper understanding of the subject in their chemistry coursework. My hypothesis is that as students learn Chemistry Change they build from experience and logical reasoning then relate chemistry specific ideas in a pair-wise fashion before making more complete multi-relational links for deeper understanding of Chemistry Change. This proposed progression of student learning, which starts at Notions, moves to Recognition, and then to Formulation and Construction.The theoretical study is the base of the following researches. Some important concepts and theories were discussed and summarized which includes big ideas, learning progressions and conceptual understanding for chemistry change. Basing on numerous literatures analysis and synthesis, and then hypothetical learning progression was developed in this dissertation research.Big ideas’ study included misconceptions, conceptual change, conceptual understanding and conceptual developing. Though the researchers didn’t agree with the definition of learning progression, they had developed some typical models including BEAR, CCD and Chem Query.ChemQuery was an assessment system that used a framework of the big ideas in chemistry and criterion-referenced analysis using item response theory to map students’ thinking progress. It could diagnose the students’ present thinking, misconceptions and next development path, and guided students’ thinking to more philosophical understanding. ChemQuery assessment system provided important methodological basis to construct learning progression model and develop measurement instruments.In empirical research, the measurement instrument of learning progression for Chemistry Change was developed, and it used in Pilot-test I and II in order to modify hypothetical learning progression based on the analysis of data through Rasch modeling. This measurement instrument had good reliability and validity and reached the psychometric indicators. All empirical dates showed that the measurement instrument had good consistency and stability. The developed measurement instrument was used to assess students’ understanding of Chemistry Change. The large samples were from high school students and chemistry freshman. The research resultsfurther validated the stability of the measurement instrument, and it revealed that there were significant differences between different grades in understanding chemical change. In term of quantitative and qualitative analysis of students’ response, the research captured conceptual understanding progression, thinking characteristics and distribution in the different grades.The research results had showed that, the developed measurement instrument had good reliability and validity and reached the psychometric indicators; The students learn big idea of Chemistry Change which starts at Notions, moves to Recognition, and then to Formulation and Construction from pre-instruction to deeper understanding of the subject in their chemistry coursework; High school and chemistry freshman gradually improve the ability to understand Chemical Change, and built up a scientific conceptual understanding model. There were significant differences between different grades in understanding Chemical Change. Grade10 students appropriately stand in level2, grade11,12 appropriately stand in level 3 and chemistry freshman stand in level4 of learning progression of Chemical Change. The study also finds that misconceptions are important stage when students develop their thinking understanding.The developed learning progression for Chemistry Change is modified for three times between theoretical hypothetic and empirical research. My research gained some valuable conclusions. For example,(I) theoretical perfection: to enrich the theoretical framework of ChemQuery assessment system, reconstruct the learning model for Chemistry Change, and develop measurement instruments of learning progression by ChemQuery assessment system and has good reliability and validity.(II) practice innovation: to reveal that there were significant differences, characteristics and rules between different grades in understanding Chemical Change concept teaching, and provide important reference value for curriculum design and evaluation study.In my dissertation, there are still some shortcomings, such as the development of measurement instruments and further empirical study.