On the Role of Animated Analogies in Algorithm Visualizations

If a “picture is worth a thousand words,” then why have attempts over the past decade to use pictures and animations to replace or supplement traditional instructional methods for teaching algorithms produced such disappointing results? In an earlier paper (Hansen, Schrimpsher, & Narayanan, 1998) we described a research project based on the premise that a rethinking of algorithm animation design is required in order to harness its power to enhance learning. The key insight was that for algorithm animations to be effective, they had to be “chunked” and embedded within a context and knowledge providing hypermedia information environment. In this paper, we report on ablation studies which were designed to discover which aspects of the prototype hypermedia visualization system that was developed (called HalVis) contributed to student learning. These preliminary studies led to a surprising discovery that interactive and animated analogies appear to significantly prime learning about abstract and dynamic algorithm behaviors from subsequent visualizations. We first present the interactive features and learning modules of HalVis. Two ablation experiments conducted on HalVis are then described. This is followed by a discussion of the results, their implications and how these are shaping our future research.