Research On The Representational Competence Of Chemical Terminology For Senior School Students

The cultivation of students' key competencies is a new trend of curriculum reform at home and abroad.Developing students' disciplinary ability is the theme of the cultivation of key competencies.The representational competence of chemical terminology(RCCT)is one of the necessary abilities of middle school students to study chemistry.Chemical terminology is a kind of symbolic system that represents the composition of matter,structure,and the law of change.RCCT refers to the use of chemical terms in chemical learning to express the composition and structure of matter and the law of change,explaining chemical phenomena,predicting the nature and the change of chemical matter.We divided RCCT into three levels: understanding,mastery,and comprehensive application,which have specific behaviors at each level.Rasch Model is a single parameter model of item response theory,which has the characteristics of objective and equidistant,and has been widely accepted and applied in the field of capability measurement.We developed an assessment tool for RCCT based on Rasch Model through the construction of the competence levels,the selection of test questions,the initial test and processing data using Ministep.The unreasonable items are removed by Standardized Residual,Outfit ZSTD and Ptmeaesur-alcorr.The assessment tool is finally formed by testing again.75 students from A school in Changchun were randomly selected as subjects and the assessment was performed using this tool.The data were processed and analyzed by Ministep and SPSS 20.0.The research shows in CCRT that most of the students in Grade 1 and Grade 2have reached the level of mastery;there is no significant difference between studentsin the first and second grades;overall,there is no significant difference between boys and girls;the level of student RCCT is positively correlated with the chemical score.