Moreover, the design of future studies should allow
testing of hypotheses about the sensory channels actively
used during experimentation, and how this use of sensory
channels affected students’ cognitive load as well as
conceptual integration of multimodal information. Factors,
such as the age of the participants or, even better, prior
exposure to PME through everyday life and K-12 experi-
ences, also need to be investigated. It might be the case, for
example, that the participants of the present study who used
VME did not need the sensory input from touch because this
information was already in students’ long-term memory
from prior everyday life or K-12 experiences. Even if the
latter assumption were true, the finding of the present study
that manipulation appears to be the important aspect of
understanding physics concepts at the university level, and
not physicality as such, is still valid. Nonetheless, we still
need to know if prior exposure to physicality is necessary or
not for understanding certain physics concepts. In case it
proves to be necessary, it is important to know when the
students need to be exposed to this touch-related informa-
tion. Furthermore, the implications of such a finding for the
curriculum material and learning environments need to be
delimited. Therefore, further research is needed to illuminate
the mechanism through which physicality affects physics
learning.
A second aim of the present study was to investigate
whether exposure to partial physicality, that is, whether
combining the mode of manipulation (physical to virtual or
vice versa) in the same sequence of instructional activities as
in PME alone and in VME alone would have a differential
effect on students’ conceptual understanding compared to
PME alone and VME alone; also, to examine whether the
effect is different when physical manipulation precedes virtual
manipulation and vice versa. The findings indicated that the
two sequential combinations, in which the mode of manipu-
lation was switched, did not differ between them and from
PME alone and VME alone, thus verifying Hypothesis 4b. The
fact that the switching of mode of experimentation could occur
without affecting students’ understanding provides support to
Triona and Klahr’s (2003)
claim that the sensory input coming
from the corresponding manipulation or motor skills may not
be specifically important for learning. What appears to be
important is whether the essential variables and interactions
are retained the ‘‘same’’ between physical and virtual
manipulation conditions. Again, this conclusion needs to be
further investigated, particularly if someone considers that the
motor skills employed in both modes of manipulation were
very simple and, most probably, have already been used by the
students during K-12. For instance, there is need to investigate
questions such as ‘‘Is the switching of the manipulation mode
feasible when the motor-skills involved in the physical mode