优、差生解决有机合成的问题表征差异及其影响因素

REPRESENTATION DIFFERENCES BETWEEN SUCCESSFUL AND UNSUCCESSFUL STUDENTS IN SOLVING ORGANIC SYNTHESIS PROBLEMS AND THE INFLUENTIAL FACTORS

用两个实验探讨了大学本科化学专业优生和差生解决有机合成问题所运用的问题表征的类型及其差异。结果表明：（１）大学生解决有机合成的问题表征有三种类型；符号表征、方法表征和机理表征。（２）优生能灵活运用上述三类问题表征，特别是运用机理表征抓住问题的关键，进而采用方法表征和符号表征来解题；差生则停留于符号表征和方法表征。很少采用机理表征，而方法表征又往往选择错误，因而不能正确解题。（３）优，差生在问题表征上的差异与其知识总量和知识结构有密切相关。

Successful and unsuccessful undergraduate chemistry majors were asked to participate in this study of the types of representation and their differences in solving organic synthesis problems. Our results show that: 1)there are three types of representation used by the students: symbolic representation, methodological representation and representation of synthetic mechanism; 2 ) successful students can use all the three types skillfully. They can find out the key features of the problems by using the representation of synthetic mechanism and solve the problems by using methodological and symbolic representations. Unsuccessful students seldom use the representation of synthetic mechanism; they often use symbolic and mehtodological representations to solve the problems and often make the wrong choices of the methodological rep resentation; 3 ) the difference in their choices of problem representation is closely related to the different amount alld structure of their knowledge.