Learning Support System for Understanding Pointers Based on Pair of Program Visualizations and Classroom Practices

Abstract

In this paper, we describe a program visualization (PV) system with capability of visualizing logical data structures and concrete memory space in the execution process of a program based on teachers’ intent of instruction, and classroom practices for understanding pointers using this system. Thus far, we have developed a PV system called TEDViT which has two distinctive features: capability of customizing PV of target domain world based on teachers’ intent of instruction, and capability of simultaneous visualization in target domain world and memory image which have different levels of abstraction. Here, target domain world is a notional world of data processed by the target programs, visualized as logical data structures. However, TEDViT evenly visualizes a memory space as memory image, thus, providing insufficient support for novice learners to understand program behaviors by observing and comparing target domain world and memory image visualizations. Therefore, in this study, we extended the original TEDViT to enable teachers define highlighting expressions in PV of memory image so that they could designate focus points or provide natural language descriptions to learners. We evaluate the effect of learning support that our extended system provided to novice learners by introducing the system in actual classrooms. The evaluation results based on the score improvements between pre and post-tests suggest that our extended TEDViT and classroom practices would have a certain degree of learning effectiveness.