Extraction of Children Friendship Relations from Activity Level

Children learn to fit into society by group interaction through which they are greatly influenced by their relations with friends. Although teachers need to observe them to assist their growth and social progress and support the development of their personalities, only experienced teachers can watch children while simultaneously providing high-quality guidance. To resolve this problem, this paper proposes a mathematical and objective method that assists teachers with observation. It uses the numerical data of activity levels recorded by pedometers from which we make tree diagrams called dendrograms based on hierarchical clustering with recorded activity levels. We also calculate the children's “breadth” and “depth” of friend relations using more than one dendrogram. After the authors recorded the children's activity levels at a kindergarten for two months to evaluate our proposed method, we found that the results generally coincided with teacher remarks and evaluations of the children.