If the two representations appear similar, then where lay the difference? The clearest difference is that when
images are presented as a cognitive tool, the externalised representation carries less information. Cognition has
to account for the “expected” stages to recreate the complete animation, which is cognitively taxing. A more
interesting difference though, seems to lie in the predictive ability of animation in showing students the
“direction” of thought when images can frequently be unordered. When a sequence is shown, and then an
image, a student may be more readily prepared to “predict” as is the usual requirement in procedural type
questions.
It is not a purpose to observe the interplay between animation and verbal presentation, but its use on helping
student in the learning process. Meanwhile, both ways can occur separate or in the same time and the focus will
remain on designing an adaptable system, capable to combine what students need from both methods. This
internal mixture of the two methods will emphasise individual progress related to preferences or abilities,
forming an ideal presentation directly related to the person.
3. More Choices with Multimedia?
So far, work has shown that there is a strong reason to believe the existence of individual differences. Therefore,
an educational system that provides the two representations that are associated with these differences is unlikely
to do worse, than those that include either one or the other. The idea is to cover for individual differences in
preferring one representation to the other as well as to provide them both in parallel. Only through this, can any
interaction between the two be assessed. If there is no interaction, then one would render the other redundant
and the total impact will be no better than that obtained in the positive experiments described. If on the other
hand, an interaction does exist and is a negative one, then each of the representations would negatively affect the
other. Performance would worsen following a classroom lecture as “confusion” may result. However, if the
interaction is a form of fortification then an improvement that exceeds expectations will result. This would
imply the existence of a positive interaction between the two modalities.
4. Multimedia Data Structures Tutoring System
The selected subject was Data Structures including the concepts of Stacks, Queues, Lists and Trees. The system
is a precursor for a Multimedia Intelligent Tutoring System, which is currently under development. These topics
were presented to students in both media simultaneously; animation and verbal description. The screen was
therefore divided into two windows; one containing a carefully written description of the concept and the other
an animation that the student can start, stop, and partially control.
The module itself is represented as a Java Applet with the aim of placing the system on the Internet. It has
several sections each concerned with one of the topics listed above and each in turn has several screens
associated with it representing Terminology, Operations, Examples and Quiz. The Terminology page explains
the basic terminology students need to learn for that data structure and is purely verbal. The Operations page
shows and explains through text and animation the basic operations that can be performed. Examples include
preset exa mples represented again through both animation and textual descriptions. The Quiz page is a student
self-assessment exercise.
Students are given the full navigational freedom to go to any page they wish and repeat the animations included
as many times as they wish within the specified time allotted for the experiment. They also had the ability to
control the speed of the animation by selecting a number from 1 to 6. This was included because students
complained about the slow speed in the experiments run by Pane, Corbett, and John (1996). The loading time of
the applet was somewhat slow but the running time was appropriate since the subject matter covered only the
basic essentials of each topic. Students were urged to think of new possible cases with the basics they were
shown.
5. Experiment 1: Evaluation of the Module
The multimedia module was tested through an experiment that compared its effects on student performance to
standard classroom lectures. Additionally, the experiment tested its effects on students who already attended the
classroom lecture. This set up was based on an analysis of current evaluation techniques that are used
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