Question 1

A sample of difference scores has a mean of MD = 5 with a variance of s² = 100.If effect size is measured using Cohen's d,what is the value of d?

Accepted Answer

A) 5/10 
B) 5/100 
C) 25/100 
D) Cannot determine without knowing the sample size 
A) 5/10 
B) 5/100 
C) 25/100 
D) Cannot determine without knowing the sample size

Question 2

If a set of n = 9 difference scores has a mean of MD = 3.5 and a variance of s² = 36,then the standard error for the sample mean difference is 4 points.

Accepted Answer

A) True 
 B)False

Question 3

A repeated-measures study and an independent-measures study both produced a t statistic with df = 10.How many individuals participated in each study?

Accepted Answer

A) 12 for repeated-measures and 11 for independent-measures 
B) 12 for repeated-measures and 12 for independent-measures 
C) 11 for repeated-measures and 11 for independent-measures 
D) 11 for repeated-measures and 12 for independent-measures 
A) 12 for repeated-measures and 11 for independent-measures 
B) 12 for repeated-measures and 12 for independent-measures 
C) 11 for repeated-measures and 11 for independent-measures 
D) 11 for repeated-measures and 12 for independent-measures

Question 4

In a repeated measures study,the null hypothesis says that the mean for the sample of difference scores is equal to zero.

Accepted Answer

A) True 
 B)False

Question 5

For which of the following situations would a repeated-measures design have the maximum advantage over an independent-measures design?

Accepted Answer

A) When many subjects are available and individual differences are small 
B) When very few subjects are available and individual differences are small 
C) When many subjects are available and individual differences are large 
D) When very few subjects are available and individual differences are large 
A) When many subjects are available and individual differences are small 
B) When very few subjects are available and individual differences are small 
C) When many subjects are available and individual differences are large 
D) When very few subjects are available and individual differences are large

Question 6

Which of the following possibilities is a serious concern with a repeated-measures study?

Accepted Answer

A) You will obtain negative values for the difference scores. 
B) The results will be influenced by order effects. 
C) The mean difference is due to individual differences rather than treatment differences. 
D) All of the other options are major concerns. 
A) You will obtain negative values for the difference scores. 
B) The results will be influenced by order effects. 
C) The mean difference is due to individual differences rather than treatment differences. 
D) All of the other options are major concerns.

Question 7

A research study produces a t statistic with df = 14.For this study,which of the following designs would require a total of 30 participants?

Accepted Answer

A) An independent-measures design 
B) A repeated-measures design 
C) A matched-subjects design 
D) None of the other options would require a total of 30 participants. 
A) An independent-measures design 
B) A repeated-measures design 
C) A matched-subjects design 
D) None of the other options would require a total of 30 participants.

Question 8

A repeated-measures study comparing two treatments with a sample of n = 4 participants produces a mean of M₁ = 18 with SS = 24 for the scores in the first treatment,a mean of M₂ = 14 with SS = 18 for the scores in the second treatment,and a mean of MD = 4 with SS = 12 for the difference scores.What is the estimated standard error for the sample mean difference?

Accepted Answer

A) 4 
B) 3 
C) 2 
D) 1 
A) 4 
B) 3 
C) 2 
D) 1

Question 9

If a set of n = 9 difference scores has a mean of MD = 3.5 and a variance of s² = 36,then the sample will produce a repeated-measures t statistic of t = 3.5/2.

Accepted Answer

A) True 
 B)False

Question 10

If all participants in a repeated-measures study show roughly the same 10-point difference between treatments,then the data are likely to produce a significant value for the t statistic.

Accepted Answer

A) True 
 B)False

Question 11

In general,what is the effect of an increase in the variance for the sample of difference scores?

Accepted Answer

A) An increase in the standard error and an increase in the value of t 
B) An increase in the standard error and a decrease in the value of t 
C) A decrease in the standard error and an increase in the value of t 
D) A decrease in the standard error and a decrease in the value of t 
A) An increase in the standard error and an increase in the value of t 
B) An increase in the standard error and a decrease in the value of t 
C) A decrease in the standard error and an increase in the value of t 
D) A decrease in the standard error and a decrease in the value of t

Question 12

For a repeated-measures study comparing two treatments with a sample of n = 9 participants,the difference scores have a mean of MD = 4.90 with SS = 72.What is the estimated standard error for the sample mean difference?

Accepted Answer

A) 9 
B) 3 
C) 1 
D) √8/3 
A) 9 
B) 3 
C) 1 
D) √8/3

Question 13

If the sample size is held constant,which of the following will produce the widest 90% confidence interval for the population mean difference for a repeated-measures study?

Accepted Answer

A) MD = 5 with s2 = 5 for the difference scores 
B) MD = 5 with s2 = 10 for the difference scores 
C) MD = 3 with s2 = 10 for the difference scores 
D) MD = 3 with s2 = 20 for the difference scores 
A) MD = 5 with s2 = 5 for the difference scores 
B) MD = 5 with s2 = 10 for the difference scores 
C) MD = 3 with s2 = 10 for the difference scores 
D) MD = 3 with s2 = 20 for the difference scores

Question 14

A repeated-measures experiment and a matched-subjects experiment each produce a t statistic with df = 10.How many individuals participated in each study?

Accepted Answer

A) 11 for repeated and 11 for matched 
B) 11 for repeated and 12 for matched 
C) 11 for repeated and 22 for matched 
D) 12 for repeated and 12 for matched 
A) 11 for repeated and 11 for matched 
B) 11 for repeated and 12 for matched 
C) 11 for repeated and 22 for matched 
D) 12 for repeated and 12 for matched

Question 15

A repeated-measures study and an independent-measures study both produce a t statistic with df = 20.The repeated-measures study used more subjects than the independent-measures study.

Accepted Answer

A) True 
 B)False

Question 16

A repeated-measures study with a sample of n = 16 participants produces a repeated-measures t = 2.00.If effect size is measured using r²,then r² = 4/20.

Accepted Answer

A) True 
 B)False

Question 17

A set of n = 16 difference scores has a mean of MD = 4 and a variance of s² = 36.Cohen's d for this sample is d = 4/6.

Accepted Answer

A) True 
 B)False

Question 18

Compared to an independent-measures design,a repeated-measures study is more likely to find a significant effect because it reduces the contribution of variance due to ______.

Accepted Answer

A) time-related factors 
B) order effects 
C) the effect of the treatment 
D) individual differences 
A) time-related factors 
B) order effects 
C) the effect of the treatment 
D) individual differences

Question 19

A researcher would like to compare two treatment conditions with a set of 30 scores in each treatment.If a repeated-measures design is used,the study will require n = 60 participants.

Accepted Answer

A) True 
 B)False

Question 20

A researcher would like to evaluate the effectiveness of a pain-relief patch designed for lower back pain.Prior to testing the patch,each of n = 8 patients rates the current level of back pain on a scale from 1 to 10.After wearing the patch for 90 minutes,a second pain rating is recorded.The data are as follows:
 $$\begin{array} { r c } 
\text { Before } & \text { After } \
\hline 6 & 2 \
8 & 3 \
9 & 4 \
8 & 1 \
10 & 2 \
5 & 3 \
9 & 8 \
7 & 7
\end{array}$$ 
a.Compute the mean and variance for the sample of difference scores.
b.Do the results indicate a significant difference? Use a two-tailed test with α = .05
c.Compute Cohen's d to measure the size of the effect.

Accepted Answer

a.MD = -4 and s² = 8

A sample of difference scores has a mean of MD = 5 with a variance of s² = 100.If effect size is measured using Cohen's d,what is the value of d?

If a set of n = 9 difference scores has a mean of MD = 3.5 and a variance of s² = 36,then the standard error for the sample mean difference is 4 points.

A repeated-measures study and an independent-measures study both produced a t statistic with df = 10.How many individuals participated in each study?

In a repeated measures study,the null hypothesis says that the mean for the sample of difference scores is equal to zero.

For which of the following situations would a repeated-measures design have the maximum advantage over an independent-measures design?

Which of the following possibilities is a serious concern with a repeated-measures study?

A research study produces a t statistic with df = 14.For this study,which of the following designs would require a total of 30 participants?

If a set of n = 9 difference scores has a mean of MD = 3.5 and a variance of s² = 36,then the sample will produce a repeated-measures t statistic of t = 3.5/2.

If all participants in a repeated-measures study show roughly the same 10-point difference between treatments,then the data are likely to produce a significant value for the t statistic.

In general,what is the effect of an increase in the variance for the sample of difference scores?

For a repeated-measures study comparing two treatments with a sample of n = 9 participants,the difference scores have a mean of MD = 4.90 with SS = 72.What is the estimated standard error for the sample mean difference?

If the sample size is held constant,which of the following will produce the widest 90% confidence interval for the population mean difference for a repeated-measures study?

A repeated-measures experiment and a matched-subjects experiment each produce a t statistic with df = 10.How many individuals participated in each study?

A repeated-measures study and an independent-measures study both produce a t statistic with df = 20.The repeated-measures study used more subjects than the independent-measures study.

A repeated-measures study with a sample of n = 16 participants produces a repeated-measures t = 2.00.If effect size is measured using r²,then r² = 4/20.

A set of n = 16 difference scores has a mean of MD = 4 and a variance of s² = 36.Cohen's d for this sample is d = 4/6.

Compared to an independent-measures design,a repeated-measures study is more likely to find a significant effect because it reduces the contribution of variance due to ______.

A researcher would like to compare two treatment conditions with a set of 30 scores in each treatment.If a repeated-measures design is used,the study will require n = 60 participants.

Introduction to Statistics.

Frequency Distributions.

Central Tendency.

Variability.

z-Scores: Location of Scores and Standardized Distributions.

Probability.

Probability and Samples: The Distribution of Sample Means.

Introduction to Hypothesis Testing.

Introduction to the t Statistic

The t Test for Two Independent Samples

Introduction to Analysis of Variance

Repeated-Measures and Two-Factor Analysis of Variance

Correlation and Regression.

The Chi-Square Statistic: Tests for Goodness of Fit and Independence

Filters

Exam 11: The t Test for Two Related Samples

A sample of difference scores has a mean of MD = 5 with a variance of s² = 100.If effect size is measured using Cohen's d,what is the value of d?

If a set of n = 9 difference scores has a mean of MD = 3.5 and a variance of s² = 36,then the standard error for the sample mean difference is 4 points.

A repeated-measures study and an independent-measures study both produced a t statistic with df = 10.How many individuals participated in each study?

In a repeated measures study,the null hypothesis says that the mean for the sample of difference scores is equal to zero.

For which of the following situations would a repeated-measures design have the maximum advantage over an independent-measures design?

Which of the following possibilities is a serious concern with a repeated-measures study?

A research study produces a t statistic with df = 14.For this study,which of the following designs would require a total of 30 participants?

If a set of n = 9 difference scores has a mean of MD = 3.5 and a variance of s² = 36,then the sample will produce a repeated-measures t statistic of t = 3.5/2.

If all participants in a repeated-measures study show roughly the same 10-point difference between treatments,then the data are likely to produce a significant value for the t statistic.

In general,what is the effect of an increase in the variance for the sample of difference scores?

For a repeated-measures study comparing two treatments with a sample of n = 9 participants,the difference scores have a mean of MD = 4.90 with SS = 72.What is the estimated standard error for the sample mean difference?

If the sample size is held constant,which of the following will produce the widest 90% confidence interval for the population mean difference for a repeated-measures study?

A repeated-measures experiment and a matched-subjects experiment each produce a t statistic with df = 10.How many individuals participated in each study?

A repeated-measures study and an independent-measures study both produce a t statistic with df = 20.The repeated-measures study used more subjects than the independent-measures study.

A repeated-measures study with a sample of n = 16 participants produces a repeated-measures t = 2.00.If effect size is measured using r²,then r² = 4/20.

A set of n = 16 difference scores has a mean of MD = 4 and a variance of s² = 36.Cohen's d for this sample is d = 4/6.

Compared to an independent-measures design,a repeated-measures study is more likely to find a significant effect because it reduces the contribution of variance due to ______.

A researcher would like to compare two treatment conditions with a set of 30 scores in each treatment.If a repeated-measures design is used,the study will require n = 60 participants.

Introduction to Statistics.

Frequency Distributions.

Central Tendency.

Variability.

z-Scores: Location of Scores and Standardized Distributions.

Probability.

Probability and Samples: The Distribution of Sample Means.

Introduction to Hypothesis Testing.

Introduction to the t Statistic

The t Test for Two Independent Samples

Introduction to Analysis of Variance

Repeated-Measures and Two-Factor Analysis of Variance

Correlation and Regression.

The Chi-Square Statistic: Tests for Goodness of Fit and Independence

Filters