SALSA and ALVIS: A language and system for constructing and presenting low fidelity algorithm visualizations

Computer science educators have traditionally used algorithm visualization (AV) software to create graphical representations of algorithms that are later used as visual aids in lectures, or as the basis for interactive labs. Based on ethnographic field studies we have conducted in an undergraduate algorithms course, we advocate an alternative teaching approach in which students use simple art supplies to construct and present their own visualizations to their peers and instructor for feedback and discussion. To support this approach, we have build SALSA and ALVIS, a prototype language and system that enable students to (a) quickly construct rough, unpolished ("low fidelity") visualizations in much the same way they would do so with simple art supplies, and (b) interactively present those visualizations to an audience. Our prototype pioneers a novel technique for programming visualizations based on spatial relations, and a novel presentation interface that supports reverse execution and dynamic mark-up and modification.