2012 Volume 6 Issue 1 Pages 10-18
The author has been developing a system called PREX which supports beginners who try to understand how to program. This paper describes the functions of PREX and the features of PREX, that is, the line editor and structure editor which doesn't require students to enter statements through keyboard and COPS value which stands for “complexity of program structures.” COPS value is also used to represent the degree of students' understanding. Finally, various problems to be resolved to enhance the usefulness of PREX are discussed.