Research On The Types Of Reasoning Of Middle School Students When Constructing The Explanation Of Dissolution Phenomenon

After the study of science courses,students should not only master the basic scientific knowledge,but also develop and improve the ability of scientific thinking to explain the phenomena of life from a scientific perspective.Reasoning plays an important role in thinking.There are many types of reasoning in the students' explanations.However,teachers tend to focus on the correctness of the knowledge and ignore the complex reasoning in the process of students' explanations.Dissolution is a basic conception and a common phenomenon.Previous studies found that students presented a variety of explanations for dissolution: explanations were based on their daily life experiences;explanations were the combination of the teacher's teaching knowledge and own knowledge;explanations were consistent with the textbooks.From previous literature,it found that students were involved in various types of reasoning.What are the different types of reasoning when explaining the dissolution phenomenon? There are many kinds of reasoning modes in scientific explanation(e.g.,rule-based reasoning,statistical/probabilistic reasoning,causal reasoning).This study focuses on the types of reasoning when students explain the dissolution phenomenon in causal reasoning mode.On the basis of summarizing the current international research results on causal explanation and causal reasoning,this article constructed an analytical framework for middle school students to characterise the types of reasoning about dissolution phenomenon,from the perspective of causal relationship and the complexity of explanation.Taking the dissolution of salt and sucrose as examples,169 middle school students(grades 9-12)were tested.We imported all data in MAXQDA2018 software.The data collected in the form of written explanations and drawing were analyzed by identifying the explanatory components(conditions,entities,properties,activities and organization)and paying attention to the cause-effect relationship involved in explanations.The results confirmed the theoreticalassumption,and shown that there were five different types of reasoning: simple descriptive reasoning,fuzzy causal reasoning,linear causal reasoning,interactive causal reasoning and mechanism causal reasoning.Among the five types of reasoning,the simple description type accounted for the largest proportion,while the interactive causal reasoning and mechanism causal reasoning accounted for a small proportion.Overall,middle school students showed a rich reasoning process,in which less than 1/3 of students carried out causal reasoning.With the increase of grades,the proportion of simple description reasoning increased and causal reasoning decreased.SPSS20.0 software was used to test the differences of reasoning among students of different grades.It was found that when explaining the dissolution of salt and sucrose,there were significant differences in the types of reasoning between junior three students and senior two students,junior three students and senior three students.Finally,according to the research results,the implications of this study to science education was discussed.In classroom teaching,teachers should attach importance to the explanation of students' self-construction,teaching students causal logic;promoting the deep learning.The value of this study lies in revealing the rich reasoning process of students,proposing that there are five different types of reasoning in explaining the dissolution phenomenon of middle school students,and finding that the complexity of students' explanation is related to carrying out different degrees of causal reasoning.The purpose of this study is to draw the attention of researchers to the process of reasoning in students' explanation activities.