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.