Software Visualization and Education - Introduction

Education has a distinguished history within SV. In fact, one of the most significant SV systems Sorting Out Sorting (SOS) [1, 2] was created to support students. SOS is a 30 minute film which describes nine sorting algorithms. The most referenced part of the film is one of the final scenes where a ‘grand race’ of the nine algorithms is depicted as nine simultaneously animated cartesian graphs. This scene, shown in figure 1, clearly indicates the different behaviour and performance of the nine algorithms. The impact of SOS was so profound that even today, over 20 years later, sorting is the most common domains used for demonstrating algorithm animation systems. A second early piece of significant work was the computer lab at Brown University [3]. From 1983 algorithms and data structure courses have been taught in a classroom where each student has a dedicated networked workstation (initially Apollo, now Sun). Using the network instructors animating displays are copied to the students’ screens. Although never formally evaluated anecdotal evidence indicated that the classroom is an extremely valuable resource for the students. The main problems encountered were associated with the effort which instructors had to put in to design, integrate and maintain the animations. In the early days the main tool used with the computer lab at Brown was BALSA [4], which provided an elegant environment for programmers to create animations based on an extension of the classical graphics model-renderer paradigm.