Preliminary Study On The Development Of Combinatorial Reasoning Ability In Primary And Middle School Students

The development of the student's scientific reasoning ability is one of the most important objectives on scientific education, and it never equals the gain of general knowledge and skills. Its formation is a slow process and has its own features and laws. Combinatorial reasoning refer that several variables are reasoned at the same time, that is, a series of different variables are pondered simultaneously. Furthermore, not only one or all of variables results in a series of variables can be determined, but also some combinatorial results can be measured.As an important reasoning type of scientific reasoning abilities, development of the student's combinatorial ability has become a research issue attracting increasing concern to the foreign scholars. But in my country, the study is very little about the combination between the development of combinatorial reasoning ability and specific subjects, especially the combination between combinatorial reasoning ability and scientific subjects. So learning about the situation and development of the combinatorial reasoning ability in primary and middle school students,it is very significant to improve the student's scientific reasoning ability and cognitive development.This study uses the two interview tools of piaget's"colorless liquid experiment"and"pendulum experiment"which has been improved. The investigation about development of combinatorial reasoning ability is done by way of clinical interview, which is conducted by eighty students, grade 1, grade 3, grade 5, grade 7, grade 9 and over grades in the Guilin Qingfeng experimental school in Guangxi and the middle school No.2 attached to Guangxi Normal University and other schools. The conclusions are as follows:In general, (1) with completing combinatorial reasoning tasks in the experiment by the students, it is the fastest-growing stage in grade 3 to grade 5 on the time of experiment which the students try their best to do, however, it is negative growth trend obviously in grade 7 to grade 9 and over grades, which even close to the level of grade 3 or grade 5. (2) It grows with grade that the combinatorial number of variables and object (element) is putted in by students. (3) It increases with the time of experiment that the combinatorial number of variables and objects (element) is putted in by students from grade 1 to grade 7, but from grade 7 to grade 9 and over grades, it is obviously upward trend to the combinatorial number of variables and objects (element) with decreasing of experiment. (4) It is the fastest growing period from grade 7 to grade 9 and over grades that the combinatorial number of the object (element) is putted in by the students, however, the rapidest increasing period is from grade 3 to grade 5 on the combinatorial number of variables. (5)Reduction on the number of experiment and increasing on combinatorial number are the form of improvement of the students'combinatorial ability. (6) Every grade in development of combinatorial reasoning ability shows its cognitive characteristics and corresponding cognitive conflict (or cognitive difficulties). (7) From the trend on the significant changes of experimental times and the results of interviews, it appears in grade 7 to the turning point of development of combinatorial reasoning ability, and the qualitative leap stage is in grade 9 and over grades.In addition, after combinatorial number is regarded as variables in the completion of combinatorial reasoning process in two experiments and the analysis of one yuan variance is carried out, the result of the multiple comparison shows there are very significant differences between all grades.In colorless liquid experiment, when the time of experiment is regarded as variables and the analysis of one yuan variance is carried out, the multiple comparison show that there are very significant differences in all grades apart from grade 3, grade 9 and over grades. However, in pendulum experiment, the results show significant difference exists between grade 1 and grade 3, grade 5, grade 9 and over grades, but there is very significant difference to the rest of all grades.In conclusion, this paper is based on the reflection of interview process and interview conclusion carefully. According to the preliminary conclusions by the study, it is intended to make some reference suggestion to the teaching of scientific education.