Question 1

The effect size d depends on which of the following?

Accepted Answer

A)    
B)  n 
C)  power 
D)    
A)    
B)  n 
C)  power 
D)    D

Question 2

If sample size is quite small and the decision is to reject the null hypothesis,

Accepted Answer

A)  the test should probably be repeated 
B)  the true difference is more likely to be substantial 
C)  the level of significance should be lowered 
D)  one should shift from a one-tailed test to a two-tailed test 
A)  the test should probably be repeated 
B)  the true difference is more likely to be substantial 
C)  the level of significance should be lowered 
D)  one should shift from a one-tailed test to a two-tailed test B

Question 3

On the basis of the results for a large random sample of males from his university, Professor Flagg reports: "The mean height for my sample fell significantly below 6 feet."
(a)Explain in precise statistical terms the meaning of Professor Flagg's statement.
(b)Does the statement indicate that the mean height for males at his university falls below 6 feet by an important amount (i.e., that he is teaching at a university of "shorties")
(c)What is one possible reason (other than very short students) for the "significance" of his results. Explain.

Accepted Answer

(a)    
 tested and rejected; conclusion: 
   (b) no; it indicates nothing about how far below 
(c) a very large sample will result in a small   
 and rejection of 
   even for a small discrepancy between 
   and the hypothesized value of 6.

Question 4

If sample size is very small and the decision is to retain the null hypothesis,

Accepted Answer

A)  there is greater likelihood that a real difference may have been overlooked 
B)  one may place special confidence in the correctness of the conclusion 
C)  if the conclusion is in error, the error is probably inconsequential 
D)  the level of significance should be raised 
A)  there is greater likelihood that a real difference may have been overlooked 
B)  one may place special confidence in the correctness of the conclusion 
C)  if the conclusion is in error, the error is probably inconsequential 
D)  the level of significance should be raised

Question 5

If   
 is false,

Accepted Answer

A)  the probability of a Type II error is zero 
B)  the probability of a Type II error is   
C)  the power of the test is zero 
D)  the power of the test is   
A)  the probability of a Type II error is zero 
B)  the probability of a Type II error is   
C)  the power of the test is zero 
D)  the power of the test is

Question 6

Sample size affects power because of its effect on

Accepted Answer

A)  random sampling variation 
B)  d 
C)  sample standard deviations 
D)  distribution shapes 
A)  random sampling variation 
B)  d 
C)  sample standard deviations 
D)  distribution shapes

Question 7

If   
 is true,

Accepted Answer

A)    
 is zero 
B)     is zero 
C)  the power of the test is .95 if   
D)  the probability of a Type II error is   
A)    
 is zero 
B)     is zero 
C)  the power of the test is .95 if   
D)  the probability of a Type II error is

Question 8

The ability to ascertain appropriate size of sample(s) required to test a particular hypothesis depends on the specification of

Accepted Answer

A)    
B)    
C)  the size of difference that would be considered to be important 
D)  all of the above 
A)    
B)    
C)  the size of difference that would be considered to be important 
D)  all of the above

Question 9

A Type II error may well be desirable when

Accepted Answer

A)  power is very large 
B)  d is very small 
C)  the probability of a Type II error is very large 
D)    is very small 
A)  power is very large 
B)  d is very small 
C)  the probability of a Type II error is very large 
D)    is very small

Question 10

Suppose that 18 out of 54 identical repetitions of an experiment comparing two methods of instruction lead to non-significant results. If method of instruction does, in fact, have an effect, our best estimate of power for this situation is

Accepted Answer

A)  .67 
B)  .18 
C)  .33 
D)  .36 
A)  .67 
B)  .18 
C)  .33 
D)  .36

Question 11

When   
 is .05, the probability of a Type II error is

Accepted Answer

A)  .05 
B)  .025 
C)  .95 
D)  not determinable from the information given 
A)  .05 
B)  .025 
C)  .95 
D)  not determinable from the information given

Question 12

The power of a test is most closely related to

Accepted Answer

A)  the level of significance 
B)  procedures for estimation 
C)  the probability of committing a Type I error 
D)    
A)  the level of significance 
B)  procedures for estimation 
C)  the probability of committing a Type I error 
D)

Question 13

If   
 is selected to be .05 rather than .01,

Accepted Answer

A)  the probability of committing a Type I error will be greater 
B)  the power of the test will be lower 
C)    
will be increased 
D)  there is greater likelihood of claiming that   
 is false when it is really true 
A)  the probability of committing a Type I error will be greater 
B)  the power of the test will be lower 
C)    
will be increased 
D)  there is greater likelihood of claiming that   
 is false when it is really true

Question 14

In general, the larger the sample size, the

Accepted Answer

A)  less the risk of a Type II error 
B)  greater the power of the test 
C)  more likely   
 will be rejected when it should be 
D)  more likely all of the above are to be true 
A)  less the risk of a Type II error 
B)  greater the power of the test 
C)  more likely   
 will be rejected when it should be 
D)  more likely all of the above are to be true

Question 15

The concept of power requires

Accepted Answer

A)    
 to be true 
B)    
 to be false 
C)    to be false 
D)  (a) or (b) above 
A)    
 to be true 
B)    
 to be false 
C)    to be false 
D)  (a) or (b) above

Question 16

If the value of   
 is not known

Accepted Answer

A)    
 cannot be established 
B)  a proper estimate of   
 cannot be made 
C)    
 is indeterminate 
D)  it is not possible to decide whether a one-tailed test or a two-tailed test should be made 
A)    
 cannot be established 
B)  a proper estimate of   
 cannot be made 
C)    
 is indeterminate 
D)  it is not possible to decide whether a one-tailed test or a two-tailed test should be made

Question 17

When   
 is .05, the probability of a Type II error is

Accepted Answer

A)  .05 
B)  .025 
C)  .95 
D)  not determinable from the information given 
A)  .05 
B)  .025 
C)  .95 
D)  not determinable from the information given

Question 18

In general, reducing the risk of committing a Type I error

Accepted Answer

A)  reduces the risk of committing a Type II error 
B)  reduces the power of the test 
C)  increases the power of the test 
D)  has no effect on any of the above 
A)  reduces the risk of committing a Type II error 
B)  reduces the power of the test 
C)  increases the power of the test 
D)  has no effect on any of the above

Question 19

is

Accepted Answer

A)    
B)  the probability of a Type I error 
C)  the probability of overlooking a true difference 
D)  the probability of claiming a true difference when none exists 
A)    
B)  the probability of a Type I error 
C)  the probability of overlooking a true difference 
D)  the probability of claiming a true difference when none exists

Question 20

A Type II error is committed when

Accepted Answer

A)  a true null hypothesis is rejected 
B)  a false null hypothesis is retained 
C)  a true alternative hypothesis is retained 
D)    
 is higher than it should be 
A)  a true null hypothesis is rejected 
B)  a false null hypothesis is retained 
C)  a true alternative hypothesis is retained 
D)    
 is higher than it should be

The effect size d depends on which of the following?

If sample size is quite small and the decision is to reject the null hypothesis,

If sample size is very small and the decision is to retain the null hypothesis,

If is false,

Sample size affects power because of its effect on

If is true,

The ability to ascertain appropriate size of sample(s) required to test a particular hypothesis depends on the specification of

A Type II error may well be desirable when

Suppose that 18 out of 54 identical repetitions of an experiment comparing two methods of instruction lead to non-significant results. If method of instruction does, in fact, have an effect, our best estimate of power for this situation is

When is .05, the probability of a Type II error is

The power of a test is most closely related to

If is selected to be .05 rather than .01,

In general, the larger the sample size, the

The concept of power requires

If the value of is not known

When is .05, the probability of a Type II error is

In general, reducing the risk of committing a Type I error

is

A Type II error is committed when

Introduction

Frequency Distributions, Percentiles,

Graphic Representation of Frequency Distributions

Central Tendency

Variability and Standard Z Scores

Standard Scores and the Normal Curve

Correlation

Prediction

Interpretive Aspects of Correlation and Regression

Probability

Random Sampling and Sampling Distributions

Introduction to Statistical Inference: Testing Hypotheses About Single Means Z and T

Testing Hypotheses About the Difference Between Two Independent Groups

Testing for a Difference

Inference About Correlation Coefficients

An Alternative to Hypothesis Testing: Confidence Intervals

Testing for Differences Among Three or More Groups: One-Way Analysis of Variance and Some Alternatives

Factorial Analysis of Variance

Chi-Square and Inference About Frequencies

Some Almost Assumption-Free Tests

Filters

Exam 13: Interpreting the Results of Hypothesis Testing: Effect Size, Type I and Type II Errors, and Power

The effect size d depends on which of the following?

If sample size is quite small and the decision is to reject the null hypothesis,

If sample size is very small and the decision is to retain the null hypothesis,

If is false,

Sample size affects power because of its effect on

If is true,

The ability to ascertain appropriate size of sample(s) required to test a particular hypothesis depends on the specification of

A Type II error may well be desirable when

Suppose that 18 out of 54 identical repetitions of an experiment comparing two methods of instruction lead to non-significant results. If method of instruction does, in fact, have an effect, our best estimate of power for this situation is

When is .05, the probability of a Type II error is

The power of a test is most closely related to

If is selected to be .05 rather than .01,

In general, the larger the sample size, the

The concept of power requires

If the value of is not known

When is .05, the probability of a Type II error is

In general, reducing the risk of committing a Type I error

is

A Type II error is committed when

Introduction

Frequency Distributions, Percentiles,

Graphic Representation of Frequency Distributions

Central Tendency

Variability and Standard Z Scores

Standard Scores and the Normal Curve

Correlation

Prediction

Interpretive Aspects of Correlation and Regression

Probability

Random Sampling and Sampling Distributions

Introduction to Statistical Inference: Testing Hypotheses About Single Means Z and T

Testing Hypotheses About the Difference Between Two Independent Groups

Testing for a Difference

Inference About Correlation Coefficients

An Alternative to Hypothesis Testing: Confidence Intervals

Testing for Differences Among Three or More Groups: One-Way Analysis of Variance and Some Alternatives

Factorial Analysis of Variance

Chi-Square and Inference About Frequencies

Some Almost Assumption-Free Tests

Filters