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Chapter 16: One-Way Analysis of Variance
Note:
The term treatment can also refer to the populations which are being
analyzed. For example, if we are comparing the average income for four
different counties in a particular state, we may refer to the four populations
(counties) as four treatments.
Example 16-6:
A farmer would like to determine whether there is a
difference in the average weight gain for five randomly selected groups of
his beef cattle. There were five different feed mixes and each group was fed
equal amounts of the same feed mix each day for a period of time. Note that
only one feed mix was used for each group. Identify the factor, treatment
levels, experimental units, response variable, and the type of factor for this
experiment.
Solution:
Factor
feed mixes;
Treatment levels
the five different feed mixes;
Experimental units
beef cattle;
Response variable
weight gain;
Type of factor
qualitative.
Note:
In all the discussions so far, all the examples presented involved a
single factor in the experiment. In this e-book, we will restrict our
discussions only to one factor analysis. That is, we will only deal with one-
factor or one-way ANOVA in the e-book.
Definition: One Factor or One-Way ANOVA
A one-factor or one-way ANOVA deals with experiments which involve a
single factor with different levels. These levels could be quantitative or
qualitative.