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15.3 UUhistle is designed to address known misconceptions
Visual program simulation in UUhistle is based on the idea that the learner needs to locate the next
execution step. To encourage the learner to think, there need to be many GUI operations to choose
from even if only one of them is the correct one. Allowing many ‘wrong paths’ to be taken reduces the
effectiveness and, presumably, the appeal, of mindless trial and error.
Allowing incorrect operations also provides a way of addressing students’ misconceptions about
program execution and language constructs. 4
15.3.1 A VPS system can be misconception-aware
Ben-Ari (2001b) leavens our enthusiasm with a cognitive constructivist point of view:
For the use of [an educational software visualization system] to be effective, the teacher
must (a) have a clear idea of the existing mental model of the student, (b) specify in advance
the characteristics of the mental models that the instruction is intended to produce, and (c)
explain exactly how the visualization will be instrumental in effecting the transition. This is an
immensely difficult undertaking. [For one thing,] the existing mental models of the individual
students are different and it takes quite a lot of effort to elicit even an approximation of a
cognitive structure.
Ben-Ari’s statement underlines the usefulness of knowing about the mental models and misconceptions
of individual students. Eliciting these from each student is indeed immensely difficult. A couple of things
make life easier for the visualization designer, however. First, nature constrains our knowledge-constructing
activities (see Section 6.3 above), so it is reasonable to expect there to be similarities between learners’
mental models and certain misconceptions to be more common than others. Second, creating a state of
cognitive conflict does not necessarily and always require a clear idea of the learner’s mental model. In
some cases, it is surely possible to make the learner deal with a conceptual model (visualization) so that
the learner him- or herself is in a position to discover a discrepancy between the conceptual model and
his or her own prior mental model, whatever it is like.
That having been said, Ben-Ari’s point is an important one. A visualization that directly and explicitly
addresses a learner’s misconception probably has a better chance of success than one that does not.
How can a fully automatic visualization system possibly address individual students’ misconceptions?
A visual program simulation system may fare better than most.
VPS and misconceptions
Here is one way of looking at how a VPS system may address a specific misconception that concerns
program behavior.
Level 0 By doing nothing. The system does not address the misconception. Nothing in the
visualization conflicts with the misconception.
Level 1 By showing what’s right. The system shows that what actually happens when the
program is run does not match the learner’s misconception. If the learner pays enough
attention, they may experience cognitive conflict between their understanding and the
visualization.
Level 2 By having the learner do what’s right. The VPS system requires the learner to
simulate aspects of program execution that pertain to the misconception. The system
prevents making the kind of mistake the learner would probably make if they consistently
followed through with their misconception. The learner has to perform simulation steps
that go against their misconception. The system does not encourage the learner to
contrast the accepted (correct) simulation step with any alternatives.
4 Substantial parts of Section 15.3 are replicated, with the publisher’s permission, from an earlier publication: Juha Sorva
and Teemu Sirkiä: “Context-Sensitive Guidance in the UUhistle Program Visualization System”, In Proceedings of PVW
2011, Sixth Program Visualization Workshop, pages 77–85, Darmstadt, Germany, Technische Universität Darmstadt, 2011.
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