The Department of Media and Information Systems of Teikyo University of Science & Technology regards software educations for undergraduate students as important. And so, the quality of teaching materials must be improved.This note describes two examples of systems which were used as teaching materials for software educations, one is with a very simple structure, and the other is with a complicated structure. The former is a Windows console application "Shogi Program", a kind of game program which the author developed as one of teaching materials for the freshmen course "Algorithms and Data Structures". And the structure of it is very simple, because it has no components to be connected with it and users of it always use it alone. This program looks like a program with high quality, because it has showed no defect since the first print on the text of the course and while the author developed its network versions (Web application and C/S (Client-Server) system application) for the 2004 university campus festival (2004 TUST campus festival). But , in order to improve its quality moreover, object oriented developing method is worth considering.The latter is a network application system with a reception program of a seminar and a registration program to its roll book. The author developed this system for the 2004 TUST campus festival and used it as one of teaching materials for the third-year students course "Database Application". This system has Web application version and C/S system version. And the structure of this one is complicated, because it had to be developed with managed development tool and uses DBMS (Microsoft Access), and more than one users use it simultaneously. This note describes the content and the cause of the defect of its Web application version which was caused by one 2-bytes space character specified instead of 1-byte space character by mistake. And this defect was found when the author made the third-year students to use it in the 2005 first term course "Database Application". This example of defect is educational and shows one of the most important things for developers to obey when developing managed mode applications
