Effective visualization of code history for peer assessment in programming education

Abstract

In this paper, we investigate the effectiveness of visualization of code history on peer assessment in computer science education. Peer assessment is found to be an effective learning tool for programming education. While many systems are proposed to support peer assessment in programming education, little effort has been devoted to finding ways to improve the peer assessment by assisting the students to understand the programs they are assessing. We introduce Eliph, a web-based peer assessment system for programming education with code history visualization. Eliph incorporates the visualization of character-level code history, selection-based history tracking and the integration of execution events to assist students in understanding programs written by peers, thereby leading to more effective peer assessment. In a controlled experiment performed in an undergraduate CS course, we show that Eliph helps students understand code structure and the author’s intention more clearly, and promotes higher quality of peer feedback.