Ch11: factorial designs Flashcards
What do factorial designs address?
factorial designs address research questions involving multiple IVs that potentially work together
“factors” in a factorial design refer to
independent variables and/or participant variables
simplest for of factorial design?
2x2
how many factors and how many levels are in a 2x2 design? How many conditions?
2 factors with 2 levels each. 4 conditions.
How many factors and levels in a 2x3 design? How many conditions?
2 factors, one with 2 levels and one with 3. 6 conditions
A researcher was interested in the effects of sexual arousal on the
ability to concentrate, and also wondered whether gender and age are important factors. The researcher had participants read passages that were low, medium, or high in sexual arousal content. The participants included both males and females and were divided into three age categories (18-24, 25-35, and 36-50 years). After reading
the passage, participants were asked to perform a proofreading task;
the researcher measured the number of errors detected on the task.
What are the variables of interest? What kind of design?# of conditions?
Variables of interest: gender, age, level of sexual arousal in content
2x3x3 factorial design
18 conditions
Define main effect
The OVERALL effect of each FACTOR (ignoring the other) on the dependent variable.
how many main effects are in a 2x2 factorial design?
2, because there are 2 factors
main effects are qualified by an ____
interaction
Define interactions in factorial designs
The influence of one factor depends upon the level of the second factor.
When looking at a line graph comparing factors, how can you tell whether or not there is an interaction?
If the lines are NOT parallel, there is an interaction. Especially if they cross.
——B1—B2
A1—30–30
A2–20–40
Is there a main effect?
Mean A1=30 Mean A2=30 NO MAIN EFFECT OF A Mean B1=25 Mean B2=35 THERE IS A MAIN EFFECT OF B
in a 3x3 factorial design in which an interaction existed between age and volume level, how would you word answer?
effect of age depends on volume level (volume on x axis)
How to determine interaction in three factor designs
- determine 2-way interactions by making 3 graphs comparing each pair (eg., age x location, location x gender, gender x age)
- determine 3-way interactions by plotting 2 graphs (eg., age x location for men and age x location for women)
How do you know whether or not there is a 3-way interaction?
- if both graphs look different from eachother
- different interaction of A and B at level C
When all factors/IV’s in the design are between subjects, this is called a
between-subjects factorial design.
eg., gender and age
within-subjects factorial designs
all factors/IV’s are within-subjects.
eg., type of music and type of stimulus (words/images)
Between-subjects factorial designs can be useful for avoiding ____ issues
variability
What could you do to see whether who the experimenter is is a factor in the experiment?
make who the experimenter is a variable to see if it’s a factor
How many total participants do you have in a between-subjects design and in a within-subjects design if there are 10 participants per condition (4 conditions)?
In a within subjects design: 10 participants per condition = 10 total participants
In a between-subjects design: 10 participants per condition = 40 total participants
What is a mixed-methods factorial design?
some factors are between-subjects and some are within-subjects.
-adding between-subject factors to reduce variability
In an experimental design where there are 3 factors:
-order of treatment
-experimenter
-music type
Which factors are between subject and which are within?
Between: -order of treatment -experimenter Within: -music type
What kind of factorial design is a pretest-posttest nonequivalent group design?
2x2 factorial design
-Quasi-experimental
T/F: time series design with nonequivalent control group is a factorial design
True. It would be a ? x 2 factorial design.
Quasi-experimental
