Ch11: factorial designs

Question 1

What do factorial designs address?

Answer 1

factorial designs address research questions involving multiple IVs that potentially work together

Question 2

“factors” in a factorial design refer to

Answer 2

independent variables and/or participant variables

Question 3

simplest for of factorial design?

Answer 3

2x2

Question 4

how many factors and how many levels are in a 2x2 design? How many conditions?

Answer 4

2 factors with 2 levels each. 4 conditions.

Question 5

How many factors and levels in a 2x3 design? How many conditions?

Answer 5

2 factors, one with 2 levels and one with 3. 6 conditions

Question 6

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?

Answer 6

Variables of interest: gender, age, level of sexual arousal in content

2x3x3 factorial design

18 conditions

Question 7

Define main effect

Answer 7

The OVERALL effect of each FACTOR (ignoring the other) on the dependent variable.

Question 8

how many main effects are in a 2x2 factorial design?

Answer 8

2, because there are 2 factors

Question 9

main effects are qualified by an ____

Answer 9

interaction

Question 10

Define interactions in factorial designs

Answer 10

The influence of one factor depends upon the level of the second factor.

Question 11

When looking at a line graph comparing factors, how can you tell whether or not there is an interaction?

Answer 11

If the lines are NOT parallel, there is an interaction. Especially if they cross.

Question 12

——B1—B2
A1—30–30
A2–20–40
Is there a main effect?

Answer 12

Mean A1=30
Mean A2=30
NO MAIN EFFECT OF A
Mean B1=25
Mean B2=35
THERE IS A MAIN EFFECT OF B

Question 13

in a 3x3 factorial design in which an interaction existed between age and volume level, how would you word answer?

Answer 13

effect of age depends on volume level (volume on x axis)

Question 14

How to determine interaction in three factor designs

Answer 14

• 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)

Question 15

How do you know whether or not there is a 3-way interaction?

Answer 15

• if both graphs look different from eachother

- different interaction of A and B at level C

Question 16

When all factors/IV’s in the design are between subjects, this is called a

Answer 16

between-subjects factorial design.

eg., gender and age

Question 17

within-subjects factorial designs

Answer 17

all factors/IV’s are within-subjects.

eg., type of music and type of stimulus (words/images)

Question 18

Between-subjects factorial designs can be useful for avoiding ____ issues

Answer 18

variability

Question 19

What could you do to see whether who the experimenter is is a factor in the experiment?

Answer 19

make who the experimenter is a variable to see if it’s a factor

Question 20

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)?

Answer 20

In a within subjects design: 10 participants per condition = 10 total participants
In a between-subjects design: 10 participants per condition = 40 total participants

Question 21

What is a mixed-methods factorial design?

Answer 21

some factors are between-subjects and some are within-subjects.
-adding between-subject factors to reduce variability

Question 22

In an experimental design where there are 3 factors:
-order of treatment
-experimenter
-music type
Which factors are between subject and which are within?

Answer 22

Between:
-order of treatment
-experimenter
Within:
-music type

Question 23

What kind of factorial design is a pretest-posttest nonequivalent group design?

Answer 23

2x2 factorial design

-Quasi-experimental

Question 24

T/F: time series design with nonequivalent control group is a factorial design

Answer 24

True. It would be a ? x 2 factorial design.

Quasi-experimental

Question 25

Why is a pre-test post-test with a nonequivalent control group design considered 2 x 2 factorial?

Answer 25

factor 1: When are they tested? (pretest and posttest)

factor 2: group (treatment group and control group)

Question 26

What are the null and alternative hypotheses in factorial designs?

Answer 26

For each individual factor: is thee a main effect? Is there an interaction?
eg: 2 x 2 factorial design
Hypothesis 1:
null: no main effect of "A"
alternative: main effect of "A"
Hypothesis 2:
null: no main effect of "B"
alternative: main effect of "B"
Hypothesis 3:
Null: No interaction of A x B
alternative: interaction of A x B
3 HYPOTHESES TOTAL FOR 2x2 FACTORIAL DESIGN

Question 27

What would be the hypotheses for the following eg:
A researcher is interested in whether students in different fields of study experience different levels of stress regarding exams. She is also interested in whether stress levels change as a function of how close exams are. (2x2)

Answer 27

• Hypothesis 1:
  null: proximity to exam has no effect on students’ stress level
  alternative: proximuty to exam has an effect on students’ stress level
• Hypothesis 2:
  null: stress level of psychology and business students are the same
  alternative: stress levels of psychology and business students are not the same
• Hypothesis 3:
  null: no interaction between field of study and proximity of exam
  alternative: there is an interaction between field of study and proximity to the exam

Question 28

One-way ANOVA vs factorial ANOVAS

Answer 28

• One-way ANOVA: includes only one factor

- factorial ANOVAs: have multiple effects to be tested statistically (main effects of each factor and interactions)

Question 29

p for field of study is 0.682
p for proximity to exam is 0.029
p for field of study x proximity is 0.039
Can we reject the null hypotheses?

Answer 29

• not for field of study but yes for main effect of proximity and for interaction, because they are lower than 0.05.
• The main effect of proximity was QUALIFIED by interaction

Question 30

In an experiment where the null failed to be rejected for gender, was rejected for education level, and was also rejected for an interaction between gender and education level, what does this mean?

Answer 30

• There is no main effect on scores for gender.
• there is a main effect on scores for educational level
• There is an interaction between gender and ed. level, therefore, the influence of gender depends on what level of schooling the participants are at

Question 31

Is it possible to find an interaction with no main effects? What about main effects with no interactions?

Answer 31

Yes and yes