Students' understanding of a logical structure in the definition of limit

Kyeong Hah Roh has written an article entitled An empirical study of students’ understanding of a logical structure in the definition of limit via the ε-strip activity. This article was published online in Educational Studies in Mathematics last Thursday. Here is the abstract of the article:

This study explored students’ understanding of a logical structure in defining the limit of a sequence, focusing on the relationship between ε and N. The subjects of this study were college students who had already encountered the concept of limit but did not have any experience with rigorous proofs using the ε–N definition. This study suggested two statements, each of which is written by using a relationship between ε and N, similar to the ε–N definition. By analyzing the students’ responses to the validity of the statements as definitions of the limit of a sequence, students’ understanding of such a relationship was classified into five major categories. This paper discusses some essential components that students must conceptualize in order properly to understand the relationship between ε and N in defining the limit of a sequence.