Students' Understanding Of Variability In Probability And Statistics

Recently, there has been an increasing interest in research on students' understanding of variability. But no similar research on this topic was available in our country. The main purpose of this study is to attract educators to pay more attention to variability by showing them the real situation of students' understanding of variation. In addition, this author also intended to explore the difficulties of students' understanding of variation and offer some suggestions to improve statistics education based on the research.The research methods adopted in this study were mainly qualitative but some statistical analyses were also involved. The following research questions were answered by questionaire and interviews: (1) Do the students appreciate the existence of variation? (2) What are the students' conceptions of variation size? (3) How do the students judge of a given variation is reasonable or not? (4) How do the students consider variation when they make a decision according to sample data?It was found that the students do acknowledge the existence of variation. But most of them don't have good sence of variation and actually they have no idea of how big range is appropriate for a real variation. When they considered variation size, they seemed not influenced by sample size. Many students mentioned extreme value, expected value etc when they judge a set of data is real or fake based on their knowledge of variation, but their ability of making decision by integrating data center with data spread were low.Based on the findings of this study, some suggestions for teaching, curriculum and assessment were given at the end of this thesis.