Chapter
Conclusion
The
experiment, especially the true experimental design
is often the measure of choice when attempting to
determine a cause and effect relationship.
Utilizing randomization and the pre-testing
and post-testing of both an experimental group and a
control group allows us to control for more
confounding variables than any other research
method. These confounding variables, when not addressed, can often
result in inaccurate findings.
Controlling
for confounding variables is important in research
and especially important in the experimental
designs. This
process helps us assure valid results both
internally and externally.
The threats to internal validity, those that
apply to the experimental situation itself, and
external validity, those relating to the
generalizability of our results to the real world
are also issues of great concern to researchers.
As the saying goes: garbage in, garbage out.
If we start with a flawed design we will end
up with flawed results.
As
the degree of control for each of the designs
discussed increases, the difficulty in performing
the research also increases. Feasibility is always an issue and even when the most
stringent control is used, the mere fact that the
subjects have agreed to participate in the
experiment may have a negative effect on the
studys generalizability.
Are volunteer subjects truly representative
of the population at large?
As you can see, there are varying degrees of
experimental research, but there is no perfect
experiment that controls for all possible variables
and assures us of 100% generalizability.
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