Question 1

Using the .01 level of significance means that,in the long run,

Accepted Answer

A) a Type I error occurs 1 time in 20. 
B) a Type I error occurs 1 time in 100. 
C) a Type II error occurs 1 time in 20. 
D) a Type II error occurs 1 time in 100.

Question 2

Some psychologists have argued that simple significance tests are misleading,and that a better statistic to evaluate the outcome of an experiment would be the

Accepted Answer

A) effect size. 
B) level of power. 
C) probability of a Type II error. 
D) number of participants divided by the standard deviation.

Question 3

Type I errors occur when a statistically significant result is obtained when in fact __________.

Accepted Answer

The answer of Type I errors occur when a statistically...

Question 4

One important advantage of using effect sizes is that

Accepted Answer

A) they indicate all the relevant parameters of a group of scores. 
B) they directly indicate the statistical significance of the research hypothesis. 
C) they provide the same information as statistical significance,but they permit meta-studies. 
D) they are standardized scores that make comparisons of different studies easier.

Question 5

A child psychologist conducts a study to test whether infants born prematurely begin to walk earlier than do infants in general.Which of the following scenarios represents a Type I error?

Accepted Answer

A) The psychologist concludes that premature infants do walk earlier than infants in general when the true situation is that they actually do not. 
B) The psychologist concludes that premature infants do walk earlier than infants in general when the true situation is that they actually do. 
C) The psychologist concludes that premature infants do not walk earlier than infants in general when the true situation is that they actually do. 
D) The psychologist concludes that premature infants do not walk earlier than infants in general when the true situation is that they actually do not.

Question 6

Failing to reject the null hypothesis when the research hypothesis is true is

Accepted Answer

A) effect size. 
B) power. 
C) a Type I error. 
D) a Type II error.

Question 7

If the effect size and the desired level of power are known,the power formula can be used to determine the

Accepted Answer

A) minimum meaningful difference. 
B) number of participants needed. 
C) population distribution. 
D) alpha level of the experiment.

Question 8

A child psychologist conducts a study to test whether infants born prematurely begin to walk earlier than do infants in general.Which of the following scenarios represents a Type II error?

Accepted Answer

A) The psychologist concludes that premature infants do walk earlier than infants in general when the true situation is that they actually do not. 
B) The psychologist concludes that premature infants do walk earlier than infants in general when the true situation is that they actually do. 
C) The psychologist concludes that premature infants do not walk earlier than infants in general when the true situation is that they actually do. 
D) The psychologist concludes that premature infants do not walk earlier than infants in general when the true situation is that they actually do not.

Question 9

The probability of rejecting the null hypothesis when in fact it is true is

Accepted Answer

A) a Type II error. 
B) the power of rejection. 
C) alpha. 
D) beta.

Exam 6: Making Sense of Statistical Significance:decision Errors, Effect Size, and Statistical Power