Learning by redesigning programs: support system for understanding design policy in software design patterns

Design patterns are good designs in object-oriented design and are generated experientially by predecessors. The objective of this research is to develop a learning method for understanding the experience knowledge of developing a good design, which lies behind the design patterns. Design policy to create the design patterns can be understood deeply if learners could have similar experiences to predecessors' experience through trial and error producing the design patterns. In this paper, we propose a learning method of reliving predecessors' experience by transforming a program with a design pattern into that without a design pattern (alternative solution). Additionally, we develop a support system that encourages learners of experiencing the learning method. A support system holds the knowledge of appropriate alternative solution, which reduces the benefits of object-oriented design and generates advice so that learners can generate appropriate alternative solutions. Experimental results obtained using our support system showed that the proposed method was effective for a deep understanding of design patterns and the importance of the learning method.