Comparison of Student Responses
Table 1 shows the number and percentage of students
from each group who predicted the can would collapse or
expand or who did not make a clear choice. As a result of
viewing the computer animation, it is clear that the students
in the experimental group were more likely to predict that
the can would collapse and less likely to predict that the can
would expand than students in the control group ( χ2(2) =
7.14, p = .028). Although the two sets of students were not
completely equivalent, the control group had received more
formal chemistry instruction. Therefore, any differences in
the student populations should tend to favor the control
group and not the experimental group.
Students who viewed the animations were also much less
likely to blindly apply gas laws in making their predictions.
While 23 students in the control group (33%) quoted gas
laws in their predictions, only 5 students in the experimental
group (6%) did so (z = 4.38, p < .0001).
Students who had viewed the animation were much more
likely to discuss the liquefaction (or condensation) of water.
Only 17 students in the control group (24%) mentioned the
process of condensation, whereas 50 students in the experimental
group (58%) suggested that condensation was
important (z = 4.25, p < .0001). The following quotes describe
how students who saw the animation viewed the role of the
condensation of water vapor in this process.
The water would begin to cool. The water vapor would
start to condense on the walls of the can, the can then
should, in theory, collapse. (Fall 1997)
The water vapor would be turning back to liquid. The
can would crush because molecules outside of the can
would crush into the sides, denting it in. (Fall 1997)
The students who viewed the animation provided more
responses that were deemed completely correct explanations
of the process: 9 of 70 (13%) in the control group vs 29 of
86 (34%) in the experimental group (z = 3.02, p = .0025).