The topics of the material are built on each other. The pattern goes into the details exactly to the depth that the problem is wholly understandable and traceable from the beginning to the end. Teacher categorizes the elements of the pattern into a small number of category. Students modify the pattern Students get a problem which they can solve modeled on the given pattern. The pattern is applicable in teaching many things.
Students have success solving small problems quickly.
Students can understand the related concepts easily. The main OO concepts are discussed during the course. The pattern has two or three windows of the previously discussed or developed window class. The pattern has a control object which controls the windows. The pattern has the previously discussed window class and a specialized window class.