Research

Algorithm Visualization

Collaborative Representations

CSCL Architectures

Representational Guidance

Publications

Conferences

 Software
 Outreach
 Opportunities
 Sponsors

email us

LILT, Dept. of ICS • University of Hawai`i at Manoa • 1680 East-West Road, POST 309 • Honolulu, HI 96822 • 1-808-956-3890

Algorithm Visualization Research at LILT

Chris Hundhausen, PI

Algorithm visualization (AV) software graphically illustrates how computer algorithms work. While AV software initially was believed to hold much promise as a pedagogical aid, research studies designed to substantiate its pedagogical benefits have yielded markedly mixed results. To harness the pedagogical promise of AV software, we need to rethink the theory of effectiveness that has guided its design and pedagogical use. This research begins with alternative theoretical foundation that views learning not at the level of the individual, but rather at the level of the community of practice. On this alternative view, learning is seen in terms of participating more centrally in the practices of the community.

To tailor this theoretical perspective to the particulars of the community of practice in which algorithms learning takes place, this research began with an ethnographic study of an undergraduate algorithms course in which AV software was used. Students were asked to use AV software to construct and present their own visualizations -- two activities commonly performed only by community experts (algorithms instructors). The key finding of the study was that use of conventional AV software in this way actually impedes learning within the community, because it requires students to put inordinate amounts of time into community-irrelevant activities, and because it discourages students and instructors from engaging in meaningful conversations about algorithms. On the other hand, asking students to construct and present homemade visualizations made out of simple art supplies appears to avoid these problems.

To explore this finding further, we are pursuing two parallel research directions: (1) Controlled experiments that test the hypothesis that students who construct their own, homemade visualizations will outperform (on a test of procedural understanding and recall) students who interact with a visualization constructed by an expert. (2) Development of a prototype AV system, Alvis, that supports the construction and presentation of unpolished, pen-and-paper visualizations. This research provides the beginnings of an alternative theory of effectiveness, which emphasizes the importance of students' constructing and discussing unpolished, pen-and-paper visualizations as a means of participating in a community of practice.