Question 1

A Cohen's d value of .25 may be considered to be a ______ effect.

Accepted Answer

A)   small
B)   medium
C)   large
D)   nonsignificantE) B) and C)
F) A) and B)

Question 2

The chances of making a type I error is typically equal to ______.

Accepted Answer

A)   the probability of rejecting the null hypothesis
B)   .95
C)   the region of non-rejection
D)   μE) B) and C)
F) None of the above

Question 3

A significance level of p < .01 is not "highly" significant compared to a significance level of p < .05.

Accepted Answer

A) True 
 B)False

Question 4

If there is a "perfect" relationship between two variables, how much of the variance in one variable is explained by the other variable?

Accepted Answer

A)   0%
B)   25%
C)   50%
D)   100%E) A) and B)
F) All of the above

Question 5

A type I error occurs when a researcher ______.

Accepted Answer

A)   does not reject the null hypothesis when he should
B)   rejects the alternative hypothesis
C)   rejects a true null hypothesis
D)   concludes an effect does not exists when it doesE) C) and D)
F) All of the above

Question 6

The probability of making a type I error may be represented by ______.

Accepted Answer

A)   α
B)   1 - t
C)   β
D)   1 - βE) C) and D)
F) A) and B)

Question 7

Which of the following would be considered a 'medium' effect size according to Cohen?

Accepted Answer

A)   r2 = .09
B)   r2 = .20
C)   r2 = .03
D)   r2 = .28E) A) and D)
F) B) and D)

Question 8

A ______ error may be characterized as ______.

Accepted Answer

A)   type I; saying an effect exists when it does not
B)   type II; rejecting a true null hypothesis
C)   type I; saying an effect does not exist when it does
D)   type II; rejecting a false null hypothesisE) A) and D)
F) C) and D)

Question 9

Reducing the likelihood of making a type II error involves ______.

Accepted Answer

A)   changing the research hypothesis
B)   increasing the likelihood of rejecting the null hypothesis
C)   decreasing the likelihood of rejecting the null hypothesis
D)   never rejecting the null hypothesisE) A) and D)
F) A) and C)

Question 10

How would a researcher interpret an r2 value of .43?

Accepted Answer

A)   5.7% of the variance in one variable is explained by another variable.
B)   57% of the variance in one variable is explained by another variable.
C)   43% of the variance in one variable is explained by another variable.
D)   4.3% of the variance in one variable is explained by another variable.E) B) and C)
F) A) and D)

Question 11

The probability of making a type I error is typically equal to ______.

Accepted Answer

A)   α
B)   β
C)   .95
D)   μE) A) and B)
F) A) and C)

Question 12

Why is the term "highly significant" inappropriate to use when interpreting the probability?

Accepted Answer

A)   because statistical significance is a dichotomy
B)   because statistical significance is on a continuum
C)   because p 
D)   because p < .001 is 'better' than p < .01E) A) and B)
F) None of the above

Question 13

Cohen's d is an estimate of ______.

Accepted Answer

A)   the difference between the mean and the population in standard deviation units
B)   the magnitude of the difference between the means of two groups measured in standard deviation units
C)   the magnitude of the difference between the means of two groups measured in standard error units
D)   the magnitude of the difference between the means of two groups measured in z-score unitsE) A) and D)
F) A) and C)

Question 14

A type I error may occur when a researcher makes the decision to ______.

Accepted Answer

A)   reject the null hypothesis
B)   fail to reject the null hypothesis
C)   support the alternative hypothesis
D)   prove the research hypothesisE) A) and C)
F) C) and D)

Question 15

A Cohen's d value of .60 may be considered to be a ______ effect.

Accepted Answer

A)   small
B)   medium
C)   large
D)   nonsignificantE) B) and D)
F) B) and C)

Question 16

A measure of effect size is a statistic that measures the ______.

Accepted Answer

A)   direction of the relationship between variables
B)   nature of the relationship between variables
C)   magnitude of the relationship between the sample and population
D)   magnitude of the relationship between variablesE) B) and C)
F) A) and D)

Question 17

A Cohen's d value of 1.03 may be considered to be a ______ effect.

Accepted Answer

A)   small
B)   medium
C)   large
D)   nonsignificantE) A) and B)
F) C) and D)

Question 18

Calculate the r2 statistic for t = 2.98 and two groups of 15 individuals each.

Accepted Answer

A)   .10
B)   .24
C)   .37
D)   .41E) None of the above
F) B) and D)

Question 19

How would a researcher interpret an r2 value of .27?

Accepted Answer

A)   27% of the variance in one variable is explained by another variable.
B)   73% of the variance in one variable is explained by another variable.
C)   2.7% of the variance in one variable is explained by another variable.
D)   .27% of the variance in one variable is explained by another variable.E) None of the above
F) B) and C)

Question 20

Which of the following is a range of possible values for a measure of effect size?

Accepted Answer

A)   50%-75%
B)   25%-75%
C)   10%-90%
D)   0%-100%E) None of the above
F) A) and D)

Exam 10: Errors in Hypothesis Testing, Statistical Power, and Effect Size

Reducing the likelihood of making a type II error involves ______.

Correct AnswerverifiedShow Answer

A ______ error may be characterized as ______.

Correct AnswerverifiedShow Answer

A significance level of p < .01 is not "highly" significant compared to a significance level of p < .05.

Correct AnswerverifiedShow Answer

Cohen's d is an estimate of ______.

Correct AnswerverifiedShow Answer

A Cohen's d value of .25 may be considered to be a ______ effect.

Correct AnswerverifiedShow Answer

A type I error occurs when a researcher ______.

Correct AnswerverifiedShow Answer

Why is the term "highly significant" inappropriate to use when interpreting the probability?

Correct AnswerverifiedShow Answer

The probability of making a type I error is typically equal to ______.

Correct AnswerverifiedShow Answer

How would a researcher interpret an r2 value of .27?

Correct AnswerverifiedShow Answer

A Cohen's d value of .60 may be considered to be a ______ effect.

Correct AnswerverifiedShow Answer

The chances of making a type I error is typically equal to ______.

Correct AnswerverifiedShow Answer

Calculate the r2 statistic for t = 2.98 and two groups of 15 individuals each.

Correct AnswerverifiedShow Answer

Which of the following would be considered a 'medium' effect size according to Cohen?

Correct AnswerverifiedShow Answer

How would a researcher interpret an r2 value of .43?

Correct AnswerverifiedShow Answer

A type I error may occur when a researcher makes the decision to ______.

Correct AnswerverifiedShow Answer

The probability of making a type I error may be represented by ______.

Correct AnswerverifiedShow Answer

If there is a "perfect" relationship between two variables, how much of the variance in one variable is explained by the other variable?

Correct AnswerverifiedShow Answer

A measure of effect size is a statistic that measures the ______.

Correct AnswerverifiedShow Answer

Which of the following is a range of possible values for a measure of effect size?

Correct AnswerverifiedShow Answer

A Cohen's d value of 1.03 may be considered to be a ______ effect.

Correct AnswerverifiedShow Answer

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A error may be characterized as .

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How would a researcher interpret an r² value of .27?

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Calculate the r² statistic for t = 2.98 and two groups of 15 individuals each.

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How would a researcher interpret an r² value of .43?

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