enPoly: Workbench for Understanding Polymorphism in Strong Typed Object-Oriented Language

Abstract

Polymorphism is a crucial concept in creating programs using object-oriented languages. Although understanding polymorphism requires learners to capture dynamic (behavioral) aspects of objects, current tools provide only static (structural) aspects. To address this limitation, we developed a workbench tool called “enPoly” that is a redesign of the “Anchor Garden” proposed by Miura et al. (2009). Our tool has the following two key features: (1) it shows learner s behavioral aspects of objects in an animated fashion and (2) it shows the distinction between the definition and implementation of methods through visualization, thereby promoting the understanding of the Interface concept in Java. An experimental study was conducted in which 12 students were divided into two six- student groups, one of which was the control group. All six students in the experimental group succeeded in solving the given programming task using polymorphism even though they did not succeed in their initial state. In contrast, the six students in the control group made no improvements.