Download Factorial Designs Exercise Answer Key 1. Consider the following

Factorial Designs Exercise
Answer Key
1. Consider the following data from a factorial-design experiment. The DV was “% of participants
who offered help to a stranger in distress.”
a. What is the design of this study? 2(number of bystanders) X 2 (gender) betweensubjects design.
b. Gender – two levels (male/female); Number of bystanders – two levels (0/10)
100
80
60
Male
40
Female
20
0
0
10
c.
or
100
80
60
0
40
10
20
0
Male
d.
Female
Main Effects
i. Fewer people helped when there were more bystanders. More people helped
when there were fewer bystanders.
ii. Females were more likely to help than males.
iii. There does seem to be an interaction. Females were much more likely to help
when there were no bystanders but males were only slightly more likely to help
when there were no bystanders.
2. In the factorial design experiment summarized below, the dependent variable was “Average
number of hallucinations.”
a. What is the design of this study? 2(type of drug) X 3(dose of drug) design.
14
12
10
8
LSD
6
Marijuana
4
2
0
Low
b.
Medium
High
Or
14
12
10
8
Low
6
Medium
High
4
2
0
LSD
c.
Marijuana
Main Effect for Type of Drug: There were more hallucinations for LSD than for
Marijuana.
Main Effect for Dose of Drug: As dosage increased, hallucinations went up.
d.
Yes, there appears to be an interaction. There was not much of a difference in
hallucinations for LSD and Marijuana at the low and medium doses. However, at the
high dose, LSD resulted in quite a few more hallucinations.