Teaching Binary Tree Algorithms through Visual Programming

In this paper, we show how visual programming can be used to teach binary tree algorithms. In our approach, the student implements a binary tree algorithm by manipulating abstract tree fragments (not necessarily just single nodes) in a visual way. This work contributes to visual programming research by combining elements of animation, programming, and proof to produce an educational visual programming tool. In addition, we introduce Opsis, a system we built to demonstrate the ideas in this paper. (Opsis is a Java applet and can be accessed at http://www.cs.washington.edu/homes/amir/Opsis.html.) We describe our experience with using Opsis in a data structures and algorithms course at the University of Washington. Finally, we make the claim that visual programming is an ideal way to teach data structure algorithms.