Experimental Strategies and Conceptual Change
The article The
Development of Scientific Reasoning in Knowledge-Rich Contexts
written by
Leona Schauble relates a series of experiments which give some insight as to
how conceptual change and experimental strategies effect subjects of varying
ages, ten
fifth and sixth graders and ten noncollege adults. The conclusions
drawn from the article
are relevant in determining the cognitive strengths
and weaknesses in the subjects as well
as how these strengths and weaknesses
vary as a result of differing ages. The objective of
the study was to track
changes in both the theories and reasoning strategies used by
participants
who conduct and interpret repeated cycles of experiments over several
sessions to learn about the causal structure of two physical science
systems. The exact
experiments are not needed to understand the results of
the experiments as long as the
experimentation strategies and conceptual
changes are understood.
The experimentation strategies approach tends to
emphasize concern for logical
validity, (i.e. how the problem pieces
together and why). The conceptual change approach
tends to be more concerned
with the plausibility and explanatory coherence as tests for
deciding
whether knowledge should be adopted. Schauble (1996) states that \"because
previous work focused either on the validity of strategies or the coherence
of conceptions,
it has tended to mask these close interrelations\" (p.102).
Therefore the results of the
experiments are incredibly useful in
determining how validity and coherence play
complementary roles.
As
stated earlier, it is not important that the exact nature of the experiments be
listed as
long as the reader understands their validity. Each subject was
asked to solve a series of
complex tasks in which the subjects attempted to
\"discover the causal relationships
between variables and outcomes in
multivariable contexts\" (Schauble, 1996, p.102).
The adults conducted more
informative experiments, giving them an advantage, yet both
groups showed
some improvement in understanding domain context.
The intrigue surrounding
these experiments is centered on what can be inferred from
the learning
habits observed in both the children and the adults. Even though the adults
had barely any more schooling than the children, it is not surprising that
the adults had
more complex and comprehensive experimentation strategies.
Such strategies can be
obtained through personal experience. It makes sense
that the adults would still have a
wider knowledge base to choose from,
helping them to be more systematic. However, it
is interesting that both
groups continued to use incorrect strategies long after they had
proved
invalid. Both groups tended to favor a particular strategy and attempted to
manipulate the other variables to make sense of that favored strategy.
The article does not explain this phenomena, it simply states that it did
happen. The
subjects even went as far as reverting back to old strategies
that failed on similar
experiences. This may be due to favored heuristics
that determine an individuals problem
solving skills. However, if this were
true it would seem that adults would prove even
more persistent in their
incorrect strategies as their heuristics are more fully developed.
The study
shows just the opposite. On repeated experimentation the the adults
demonstrated 79% \"comprehension\", or possible variation in the task
explored, and the
children only demonstrated 66% comprehension (Schauble,
1996, p. 110). This tends to
argue against the huerisitcs notion because
both groups began at approximately the same
comprehension levels. These
results seem to lend to the formerly discussed view of a
wider knowledge
base for adults than exist in children. These findings do not completely
discredit the heuristic notion as the study does not touch on the use of
heuristics and
therefore was not very comprehensive itself.
It is
interesting that the plan structures of the adults began as more complex but
leveled
off with that of the children upon repeated experimentation. By the
second task half of the
children were using the more complex plan structures
and the children and adults no
longer differed significantly. It can be
inferred by these results that our reasoning capacity
is something that is
inherent and varies little through out our lifetimes. This can iliminate a
lot of ambiguity in the classroom.
Teacher\'s can take the findings of
this experiment and focus less on working on plan
structures and more on
comprehensivity and eliminating inefficiency due to emphasis on
invalid,
favored strategies. The results of the experiments listed in the article are
useful in
their own right but they can also act as feeder experiments for
later research. Now that
the learning strategies have been somewhat
determined in relation to age studies can delve
deeper into what motivates
these decisions. If the motivations are found they can be
fueled or
inhibited depending on the positive or negative effects on learning. Schauble
(1996) states that there is a positive relationship between the kind of plan
structure
adopted and the percentage of valid inferences made\" (p. 110).
The article itself presented
a workable plan structure and evoked valid
inferences to be used in later research.
References
Shauble, L.
(1996). The Development of Scientific Reasoning in Knowledge-Rich
Contexts.
Developmental Psychology 32. p.102-119.