Analysis of Three-factor Designs (1 of 3)
A three-factor analysis of variance
consists of seven significance tests:
test for each of the three main effects,
a test for each of the three two-way
and a test of the three-way
Consider a hypothetical experiment investigating how
well children and adults remember. There are three factors in the
- Type of test: Subjects are either asked to recall or to recognize
the stimuli. In the recall test, subjects are asked to state the names
of as many of the stimuli as they can. On each recognition test trial,
subjects are asked to pick out the one stimulus that had been presented
from a set of four stimuli.
- Age: 10-year old children and adults are compared.
- Type of stimulus: The stimuli to be remembered are presented either as
pictures or as words.
The experiment can therefore be described as an Age (2) x Type of stimulus
(2) x Type of test (2) factorial design. There were five subjects in
each of the eight conditions. The data are shown on the next page.