Question 1

The null hypothesis states that the sample mean (after treatment)is equal to the original population mean (before treatment).

Accepted Answer

A) True 
 B)False  False

Question 2

The value obtained for Cohen's d is independent of the sample size.

Accepted Answer

A) True 
 B)False  True

Question 3

A researcher selects a sample and administers a treatment to the individuals in the sample.If the sample is used for a hypothesis test,what does the alternative hypothesis (H₁)say about the treatment?

Accepted Answer

A)  The treatment causes a change in the scores.
B)  The treatment adds a constant to each score.
C)  The treatment multiplies each score by a constant.
D)  The treatment has no effect on the scores. A

Question 4

Which of the following accurately describes a hypothesis test?

Accepted Answer

A)  A descriptive technique that allows researchers to describe a sample
B)  A descriptive technique that allows researchers to describe a population
C)  An inferential technique that uses the data from a sample to draw inferences about a population
D)  An inferential technique that uses information about a population to make predictions about a sample

Question 5

A Type I error occurs when a treatment has no effect but the decision is to reject the null hypothesis.

Accepted Answer

A) True 
 B)False

Question 6

You complete a hypothesis test using α = .05,and based on the evidence from the sample,your decision is to reject the null hypothesis.If the treatment actually does have an effect,which of the following is true?

Accepted Answer

A)  You have made a Type I error.
B)  You have made a Type II error.
C)  You might have made a Type I error, but the probability is only 5% at most.
D)  You have made the correct decision.

Question 7

Which of the following accurately describes the effect of increasing the sample size?

Accepted Answer

A)  Increases the standard error and has no effect on the risk of a Type I error
B)  Decreases the standard error and has no effect on the risk of a Type I error
C)  Increases the risk of a Type I error and has no effect on the standard error
D)  Decreases the risk of a Type I error and has no effect on the standard error

Question 8

If other factors are held constant,then increasing the sample size will increase the likelihood of rejecting the null hypothesis.

Accepted Answer

A) True 
 B)False

Question 9

The critical region for a hypothesis test consists of sample outcomes that are very unlikely to occur if the null hypothesis is true.

Accepted Answer

A) True 
 B)False

Question 10

In a research report,p < .05 indicates that the probability of a Type I error is less than .05.

Accepted Answer

A) True 
 B)False

Question 11

You complete a hypothesis test using α = .05,and based on the evidence from the sample,your decision is to reject the null hypothesis.If the treatment actually has no effect,which of the following is true?

Accepted Answer

A)  You have made a Type I error.
B)  You have made a Type II error.
C)  You might have made a Type I error, but the probability is only 5% at most.
D)  You have made the correct decision.

Question 12

A sample of n = 9 individuals is selected from a population with μ = 60 and σ = 6,and a treatment is administered to the sample.After treatment,the sample mean is M = 63.What is the value of Cohen's d for this sample?

Accepted Answer

A)  0.33
B)  0.50
C)  1.00
D)  2.00

Question 13

A Type II error occurs when a researcher concludes that a treatment has an effect but,in fact,the treatment has no effect.

Accepted Answer

A) True 
 B)False

Question 14

A researcher administers a treatment to a sample of participants selected from a population with µ = 80.If the researcher obtains a sample mean of M = 88,which combination of factors is most likely to result in rejecting the null hypothesis?

Accepted Answer

A)  σ = 5 and α = .01
B)  σ = 5 and α = .05
C)  σ = 10 and α = .01
D)  σ = 10 and α = .05

Question 15

Which of the following is directly addressed by the null hypothesis?

Accepted Answer

A)  The population before treatment
B)  The population after treatment
C)  The sample before treatment
D)  The sample after treatment

Question 16

Which of the following is an accurate definition for the power of a statistical test?

Accepted Answer

A)  The probability of rejecting a true null hypothesis
B)  The probability of supporting true null hypothesis
C)  The probability of rejecting a false null hypothesis
D)  The probability of supporting a false null hypothesis

Question 17

When is there a risk of a Type II error?

Accepted Answer

A)  Whenever H0 is rejected
B)  Whenever H1 is rejected
C)  Whenever the decision is "fail to reject H0"
D)  The risk of a Type II error is independent of the decision from a hypothesis test.

Question 18

Which of the following is an accurate definition of a Type II error?

Accepted Answer

A)  Rejecting a false null hypothesis
B)  Rejecting a true null hypothesis
C)  Failing to reject a false null hypothesis
D)  Failing to reject a true null hypothesis

Question 19

A researcher is conducting an experiment to evaluate a treatment that is expected to increase the scores for individuals in a population that is known to have a mean of μ = 80.The results will be examined using a one-tailed hypothesis test.Which of the following is the correct statement of the null hypothesis?

Accepted Answer

A)  μ > 40
B)  μ > 120
C)  μ 
D)  μ < 80

Question 20

A researcher selects a sample and administers a treatment to the individuals in the sample.If the sample is used for a hypothesis test,what does the null hypothesis (H₀)say about the treatment?

Accepted Answer

A)  The treatment causes a change in the scores.
B)  The treatment adds a constant to each score.
C)  The treatment multiplies each score by a constant.
D)  The treatment has no effect on the scores.

Exam 8: Introduction to Hypothesis Testing.

The null hypothesis states that the sample mean (after treatment)is equal to the original population mean (before treatment).

The value obtained for Cohen's d is independent of the sample size.

A researcher selects a sample and administers a treatment to the individuals in the sample.If the sample is used for a hypothesis test,what does the alternative hypothesis (H₁) say about the treatment?

Which of the following accurately describes a hypothesis test?

A Type I error occurs when a treatment has no effect but the decision is to reject the null hypothesis.

You complete a hypothesis test using α = .05,and based on the evidence from the sample,your decision is to reject the null hypothesis.If the treatment actually does have an effect,which of the following is true?

Which of the following accurately describes the effect of increasing the sample size?

If other factors are held constant,then increasing the sample size will increase the likelihood of rejecting the null hypothesis.

The critical region for a hypothesis test consists of sample outcomes that are very unlikely to occur if the null hypothesis is true.

In a research report,p < .05 indicates that the probability of a Type I error is less than .05.

You complete a hypothesis test using α = .05,and based on the evidence from the sample,your decision is to reject the null hypothesis.If the treatment actually has no effect,which of the following is true?

A sample of n = 9 individuals is selected from a population with μ = 60 and σ = 6,and a treatment is administered to the sample.After treatment,the sample mean is M = 63.What is the value of Cohen's d for this sample?

A Type II error occurs when a researcher concludes that a treatment has an effect but,in fact,the treatment has no effect.

A researcher administers a treatment to a sample of participants selected from a population with µ = 80.If the researcher obtains a sample mean of M = 88,which combination of factors is most likely to result in rejecting the null hypothesis?

Which of the following is directly addressed by the null hypothesis?

Which of the following is an accurate definition for the power of a statistical test?

When is there a risk of a Type II error?

Which of the following is an accurate definition of a Type II error?

A researcher selects a sample and administers a treatment to the individuals in the sample.If the sample is used for a hypothesis test,what does the null hypothesis (H₀) say about the treatment?