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Chapter 16: One-Way Analysis of Variance
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Another term encountered in the study of ANOVA is
experiment
. In a true
experiment, the researcher manipulates one or more independent variables in
order to determine the effect of one or more dependent variables. For
example, the researcher may want to determine the effect on the yield of a
certain crop for different fertilizers.
Definition: Experiment
An experiment is a study in which the researcher manipulates one or more
independent variables in order to determine the effect of one or more
dependent variables.
Note:
A careful statement of the problem to be solved goes a long way towards its
solution.
Example 16-4:
A researcher would like to determine whether there is a
difference in the average mileages for three different brands of gasoline.
What is the experiment in this case?
Solution:
The problem to be solved in this example is to determine whether
there are differences in the average mileage for the three different brands of
gasoline. The researcher will be using (“manipulating”) the three different
brands of gasoline in order to observe the effect on the gas mileage. Hence,
the
experiment
in this case will be the study designed to see how the brands
of gasoline affect gas mileage.
Example 16-5:
What is the experiment in
Example 16-1
?
Solution:
The problem to be solved in
Example 16-1
is to determine
whether there was a statistical significant difference between the average
number of credit hours in which the undergraduate students were enrolled
for the different classifications on that particular campus. The researcher
will be using (“manipulating”) the four different student classifications in
order to observe the effect on the number of credit hours in which the
students were enrolled. Hence, the
experiment
in this case will be the study