Skip to main content
United States
Jump To
Support
Register or Log In
Support
Register or Log In
Instructors
Browse Products
Getting Started
Students
Browse Products
Getting Started
Return to Research Methods Using R 1e Student Resources
Chapter 5 Multiple choice questions
Quiz Content
*
not completed
.
How many participants would you need to test to detect a correlation of
r
=0.5 with power of 0.5 (at α=0.05)? [Hint: you will find the functions in the
pwr
package helpful.]
Less than 10 participants
correct
incorrect
More than 15 participants
correct
incorrect
More than 25 participants
correct
incorrect
More than 50 participants
correct
incorrect
*
not completed
.
How many extra participants would you need to test in the study design from question 1 if the criterion for significance changed to α=0.01?
An extra 10 participants
correct
incorrect
An extra 15 participants
correct
incorrect
An extra 25 participants
correct
incorrect
An extra 50 participants
correct
incorrect
*
not completed
.
What is the smallest effect that can be detected using a t-test with 10 participants per group at a power of 0.8 and α=0.05?
d
= 0.14
correct
incorrect
d
= 0.37
correct
incorrect
d
= 0.98
correct
incorrect
d
= 1.32
correct
incorrect
*
not completed
.
A study testing 20 participants per group produced an effect of
d
=1, which was significant at
p
<0.05. What was the observed power for the study?
Power = 0.01
correct
incorrect
Power = 0.33
correct
incorrect
Power = 0.87
correct
incorrect
Power = 1.54
correct
incorrect
*
not completed
.
What size of effect can be detected at power of 0.3 using a chi-square test with 4 degrees of freedom and 27 observations at α=0.05?
w
= 0.37
correct
incorrect
w
= 0.52
correct
incorrect
w
= 0.73
correct
incorrect
w
= 0.89
correct
incorrect
*
not completed
.
What is the minimum sample size for a chi-square test with 12 degrees of freedom, effect size of 0.3, power of 0.8 and a significance criterion of α=0.001?
N = 35
correct
incorrect
N = 55
correct
incorrect
N = 102
correct
incorrect
N = 349
correct
incorrect
*
not completed
.
For a one-way ANOVA with 5 groups and an effect size of 0.3, what is the power with 24 participants per group (assuming α=0.05)?
Power = 0.03
correct
incorrect
Power = 0.30
correct
incorrect
Power = 0.73
correct
incorrect
Power = 0.83
correct
incorrect
*
not completed
.
What is the smallest effect size that can be detected with power=0.5 using a factorial ANOVA with (3,6) degrees of freedom at α=0.1?
f2 = 0.07
correct
incorrect
f2 = 0.69
correct
incorrect
f2 = 1.07
correct
incorrect
f2 = 1.69
correct
incorrect
*
not completed
.
Imagine a study that measures a dependent variable in 100 individuals of different ages. Which has the greater power – a t-test, where half of the subjects are in each group, or a correlation between age and the dependent variable? Assume an effect size of 0.4, and a significance level of α=0.05.
The correlation has the greater power
correct
incorrect
The t-test has the greater power
correct
incorrect
Both designs have exactly the same power
correct
incorrect
It depends if the t-test is paired or independent
correct
incorrect
*
not completed
.
Which of the following has the greatest statistical power?
A one-sample t-test with 12 observers, α=0.05, and effect size d=0.4
correct
incorrect
A chi-square test with 55 observations, α=0.01, two degrees of freedom, and effect size w=0.2
correct
incorrect
A correlation with 80 observers, α=0.05, and effect size r=0.3
correct
incorrect
A one-way ANOVA with 8 levels, an effect size of 0.3, 12 participants per group, at α=0.05
correct
incorrect
Previous Question
Submit Quiz
Next Question
Reset
Exit Quiz
Review all Questions
Submit Quiz
Are you sure?
You have some unanswered questions. Do you really want to submit?
Back to top
Printed from , all rights reserved. © Oxford University Press, 2024
Select your Country