Question 1

______ is an estimate of the magnitude of the difference between the means of two groups measured in standard deviation units.

Accepted Answer

A)   r2
B)   t2
C)   β
D)   Cohen's d

Question 2

An r2 value of .05 indicates that 5% of the variance in one variable is explained by another variable.

Accepted Answer

A) True 
 B)False

Question 3

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

Accepted Answer

A)   type I; p = α
B)   type II; 1 - α
C)   type I; p = β
D)   type II; 1 - β

Question 4

A type II error occurs when a researcher makes the decision to ______.

Accepted Answer

A)   reject the null hypothesis
B)   not reject the null hypothesis
C)   accept the alternative hypothesis
D)   prove the null hypothesis

Question 5

Which statement would be inappropriate to use when interpreting the significance level of a variable?

Accepted Answer

A)   The difference was found to be significant at the p 
B)   The difference was found to be significant at the p 
C)   The difference was found to not be significant with a p value of p > .05.
D)   The difference was found to be significant at the p <.05 level.

Question 6

Calculate Cohen's d for t = 4.22 with N = 60 for each of the two groups.

Accepted Answer

A)   .07
B)   .39
C)   .78
D)   1.11

Question 7

The percentage of variance in one variable that is accounted for by another variable is ______.

Accepted Answer

A)   r2
B)   t2
C)   d
D)   α

Question 8

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

Accepted Answer

A)   .01
B)   .05
C)   .95
D)   .99

Question 9

Using a more homogeneous sample is one strategy used by researchers to ______.

Accepted Answer

A)   increase between-group variability
B)   decrease between-group variability
C)   increase within-group variability
D)   decrease within-group variability

Question 10

Calculate the r2 statistic for t = 3.02 with N = 100 for each of the two groups.

Accepted Answer

A)   .02
B)   .04
C)   .08
D)   .09

Question 11

A researcher found that his statistic was significant at the p < .01 level, indicating it was "more" significant than if the significance level was found to be p < .05.

Accepted Answer

A) True 
 B)False

Question 12

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

Accepted Answer

A) True 
 B)False

Question 13

The only way to completely eliminate the possibility of type I error is to ______.

Accepted Answer

A)   never reject the null hypothesis
B)   always reject the null hypothesis
C)   collect data from the entire population
D)   always use non-directional hypotheses

Question 14

If major league baseball players were to be tested for steroids, a ______ error would occur if the test states a player ______ steroids when in reality he ______.

Accepted Answer

A)   type I; uses; does not
B)   type I; does not use; does not
C)   type II; uses; does not
D)   type II; uses; does

Question 15

The probability of making a type II error is typically ______.

Accepted Answer

A)   .01
B)   .05
C)   .10
D)   none of these

Question 16

The ______ statistic is a measure of effect size that may be calculated when testing the difference between two sample means.

Accepted Answer

A)   r2
B)   α
C)   t2
D)   df

Question 17

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

Accepted Answer

A)   1 - β
B)   1 - α
C)   μ
D)   none of these

Question 18

Calculate Cohen's d for t = 2.45 with N = 40 for each of the two groups.

Accepted Answer

A)   .06
B)   .28
C)   .55
D)   .79

Question 19

A type I error means that a researcher has ______.

Accepted Answer

A)   correctly concluded that an effect does not exist
B)   correctly concluded that an effect exists
C)   falsely concluded that an effect does not exist
D)   falsely concluded that an effect exists

Question 20

A type II error occurs when researchers make the decision to ______ when they ______.

Accepted Answer

A)   not reject the null hypothesis; should
B)   reject the null hypothesis; should not
C)   reject the alternative hypothesis; should not
D)   not reject the null hypothesis; should not

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

Which statement would be inappropriate to use when interpreting the significance level of a variable?

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

______ is an estimate of the magnitude of the difference between the means of two groups measured in standard deviation units.

Correct AnswerverifiedShow Answer

Using a more homogeneous sample is one strategy used by researchers to ______.

Correct AnswerverifiedShow Answer

An r2 value of .05 indicates that 5% of the variance in one variable is explained by another variable.

Correct AnswerverifiedShow Answer

A type II error occurs when researchers make the decision to ______ when they ______.

Correct AnswerverifiedShow Answer

If major league baseball players were to be tested for steroids, a ______ error would occur if the test states a player ______ steroids when in reality he ______.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The only way to completely eliminate the possibility of type I error is to ______.

Correct AnswerverifiedShow Answer

The probability of making a type II error is typically ______.

Correct AnswerverifiedShow Answer

Calculate Cohen's d for t = 2.45 with N = 40 for each of the two groups.

Correct AnswerverifiedShow Answer

A type II error occurs when a researcher makes the decision to ______.

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

The ______ statistic is a measure of effect size that may be calculated when testing the difference between two sample means.

Correct AnswerverifiedShow Answer

A researcher found that his statistic was significant at the p < .01 level, indicating it was "more" significant than if the significance level was found to be p < .05.

Correct AnswerverifiedShow Answer

Calculate Cohen's d for t = 4.22 with N = 60 for each of the two groups.

Correct AnswerverifiedShow Answer

The percentage of variance in one variable that is accounted for by another variable is ______.

Correct AnswerverifiedShow Answer

Calculate the r2 statistic for t = 3.02 with N = 100 for each of the two groups.

Correct AnswerverifiedShow Answer

A type I error means that a researcher has ______.

Correct AnswerverifiedShow Answer

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The probability of making a error may be represented by .

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An r² value of .05 indicates that 5% of the variance in one variable is explained by another variable.

Correct Answer
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A type II error occurs when researchers make the decision to when they .

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If major league baseball players were to be tested for steroids, a error would occur if the test states a player steroids when in reality he __.

Correct Answer
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Calculate the r² statistic for t = 3.02 with N = 100 for each of the two groups.

Correct Answer
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