Question 1

An independent samples t -Test with a sample size of 50 will have 48 degrees of freedom.

Accepted Answer

A) True 
 B)False  True

Question 2

The term degrees of freedom refers to how many values are free to vary in a set of values if we know the summary statistic and the number of values in the set.

Accepted Answer

A) True 
 B)False  True

Question 3

In a pilot study, Dana wants to test the significance of the improvement in mean scores from pretest to posttest.Dana should use:

Accepted Answer

A) The one-sample t-Test. 
B) The paired-samples t-Test. 
C) The independent-samples t-Test. 
D) An independent-samples t-Test with change scores. 
A) The one-sample t-Test. 
B) The paired-samples t-Test. 
C) The independent-samples t-Test. 
D) An independent-samples t-Test with change scores. B

Question 4

When using an independent-samples t-Test, which of the following is considered when calculating the degrees of freedom?

Accepted Answer

A) The number of values that are free to vary in each group if we know the mean and sample size of each group. 
B) The number of values we would need to know in each group in order to deduce the remaining values, in light of the mean and sample size of each group. 
C) Each group's sample size minus 1. 
D) When combining both groups, the overall sample size minus 2. 
E) All of these. 
A) The number of values that are free to vary in each group if we know the mean and sample size of each group. 
B) The number of values we would need to know in each group in order to deduce the remaining values, in light of the mean and sample size of each group. 
C) Each group's sample size minus 1. 
D) When combining both groups, the overall sample size minus 2. 
E) All of these.

Question 5

The t-Test formula involves calculating a t-score by:

Accepted Answer

A) Dividing the difference between two means by the standard deviation of the experimental group. 
B) Dividing the difference between two means by the standard error of the difference between means. 
C) Dividing the difference between two means by the standard deviation of the control group. 
D) Dividing the difference between two standard deviations by the difference between two means. 
A) Dividing the difference between two means by the standard deviation of the experimental group. 
B) Dividing the difference between two means by the standard error of the difference between means. 
C) Dividing the difference between two means by the standard deviation of the control group. 
D) Dividing the difference between two standard deviations by the difference between two means.

Question 6

It is appropriate to use the independent-samples t-Test when:

Accepted Answer

A) We want to compare the means of pairs of individuals who have been matched because they are similar to each other. 
B) We want to compare the means of two independent groups. 
C) We want to compare a sample statistic to a population statistic. 
D) We want to compare the means of more than two groups. 
A) We want to compare the means of pairs of individuals who have been matched because they are similar to each other. 
B) We want to compare the means of two independent groups. 
C) We want to compare a sample statistic to a population statistic. 
D) We want to compare the means of more than two groups.

Question 7

It is appropriate to use the t-Test when:

Accepted Answer

A) Comparing the means of two groups. 
B) Comparing the means of two or more groups. 
C) Comparing the means of three or more groups. 
D) Both variables are at the ratio level of measurement. 
A) Comparing the means of two groups. 
B) Comparing the means of two or more groups. 
C) Comparing the means of three or more groups. 
D) Both variables are at the ratio level of measurement.

Question 8

It is appropriate to use the paired-samples t-Test when:

Accepted Answer

A) We want to compare the means of pairs of individuals who have been matched because they are similar to each other. 
B) We want to compare the means of two independent groups. 
C) We want to compare a sample statistic to a population statistic. 
D) We want to compare the means of more than two groups. 
A) We want to compare the means of pairs of individuals who have been matched because they are similar to each other. 
B) We want to compare the means of two independent groups. 
C) We want to compare a sample statistic to a population statistic. 
D) We want to compare the means of more than two groups.

Question 9

A t distribution will provide a better estimate of the population mean and standard error than will a z distribution when the sample size is very small or badly skewed.

Accepted Answer

A) True 
 B)False

Question 10

An independent samples t -Test with a sample size of 100 will have 2 degrees of freedom.

Accepted Answer

A) True 
 B)False

Question 11

The paired-samples t-Test is used when the two groups of values that we want to compare are connected or related to each other in some way.

Accepted Answer

A) True 
 B)False

Question 12

If one group has a significant change in a paired-samples t-Test, and another group does not in its (separate) paired-samples t-Test, that signifies a significant difference between the groups.

Accepted Answer

A) True 
 B)False

Question 13

A non-parametric alternative to the t -Test can be used when dependent variable is at the ordinal level of measurement or is not distributed normally.

Accepted Answer

A) True 
 B)False

Question 14

Randy wants to see whether Intervention A is more effective than Intervention B in improving self-esteem scores.Randy conducts an experiment to see if recipients of Intervention A improve more in self-esteem from pretest to posttest than recipients of Intervention B, using the .05 level of significance.Randy conducts two paired-sample t-Tests and finds a p value of .04 for Intervention A's improvement and a p value of .06 for Intervention B's improvement.Randy then conducts an independent-samples t-Test of the posttest scores and finds a p value of .55.Which of the following statements is an appropriate conclusion from Randy's findings?

Accepted Answer

A) Intervention A is more effective than Intervention B in improving self-esteem scores. 
B) Both interventions are effective in improving self-esteem scores, but Intervention A is more effective. 
C) Both interventions are equally effective in improving self-esteem scores. 
D) We cannot conclude that either intervention is effective in improving self-esteem scores. 
A) Intervention A is more effective than Intervention B in improving self-esteem scores. 
B) Both interventions are effective in improving self-esteem scores, but Intervention A is more effective. 
C) Both interventions are equally effective in improving self-esteem scores. 
D) We cannot conclude that either intervention is effective in improving self-esteem scores.

Question 15

Suppose a study is done in which the experimental and control groups both get pretests and posttests.Which of the following is the best statistical procedure?

Accepted Answer

A) Conduct a paired-samples t-test separately for each group to see whether the experimental group's improvement is more statistically significant than the control group's improvement 
B) Conduct an independent-samples t-test that compares the posttest means only. 
C) Conduct an independent-samples t-test that compares the changes scores in the two groups. 
D) All of these are equally acceptable. 
A) Conduct a paired-samples t-test separately for each group to see whether the experimental group's improvement is more statistically significant than the control group's improvement 
B) Conduct an independent-samples t-test that compares the posttest means only. 
C) Conduct an independent-samples t-test that compares the changes scores in the two groups. 
D) All of these are equally acceptable.

Question 16

The t -Test calculates a t-score by dividing the difference between two means by the standard error of the difference between means in the theoretical sampling distribution.

Accepted Answer

A) True 
 B)False

Question 17

It is appropriate to use the t-Test when:

Accepted Answer

A) The independent and dependent variables are both at the nominal level of measurement. 
B) The independent and dependent variables are both at the ordinal level of measurement. 
C) The independent and dependent variables are both at the ratio level of measurement. 
D) The independent variable is nominal and dichotomous and the dependent variable is at the interval or ratio level of measurement. 
A) The independent and dependent variables are both at the nominal level of measurement. 
B) The independent and dependent variables are both at the ordinal level of measurement. 
C) The independent and dependent variables are both at the ratio level of measurement. 
D) The independent variable is nominal and dichotomous and the dependent variable is at the interval or ratio level of measurement.

Question 18

The independent-samples t-Test is used when we want to compare the means of two independent groups.

Accepted Answer

A) True 
 B)False

Question 19

Suppose an experiment compares two independent groups on an ordinal dependent variable.Which of the following is the most appropriate nonparametric statistical procedure

Accepted Answer

A) Mann-Whitney U test 
B) Sign test 
C) Wilcoxon matched-pairs test 
D) t-test 
A) Mann-Whitney U test 
B) Sign test 
C) Wilcoxon matched-pairs test 
D) t-test

Question 20

All t -Tests use the same t distribution regardless of the size of the sample and its standard deviation.

Accepted Answer

A) True 
 B)False

An independent samples t -Test with a sample size of 50 will have 48 degrees of freedom.

The term degrees of freedom refers to how many values are free to vary in a set of values if we know the summary statistic and the number of values in the set.

In a pilot study, Dana wants to test the significance of the improvement in mean scores from pretest to posttest.Dana should use:

When using an independent-samples t-Test, which of the following is considered when calculating the degrees of freedom?

The t-Test formula involves calculating a t-score by:

It is appropriate to use the independent-samples t-Test when:

It is appropriate to use the t-Test when:

It is appropriate to use the paired-samples t-Test when:

A t distribution will provide a better estimate of the population mean and standard error than will a z distribution when the sample size is very small or badly skewed.

An independent samples t -Test with a sample size of 100 will have 2 degrees of freedom.

The paired-samples t-Test is used when the two groups of values that we want to compare are connected or related to each other in some way.

If one group has a significant change in a paired-samples t-Test, and another group does not in its (separate) paired-samples t-Test, that signifies a significant difference between the groups.

A non-parametric alternative to the t -Test can be used when dependent variable is at the ordinal level of measurement or is not distributed normally.

Suppose a study is done in which the experimental and control groups both get pretests and posttests.Which of the following is the best statistical procedure?

The t -Test calculates a t-score by dividing the difference between two means by the standard error of the difference between means in the theoretical sampling distribution.

It is appropriate to use the t-Test when:

The independent-samples t-Test is used when we want to compare the means of two independent groups.

Suppose an experiment compares two independent groups on an ordinal dependent variable.Which of the following is the most appropriate nonparametric statistical procedure

All t -Tests use the same t distribution regardless of the size of the sample and its standard deviation.

Why Study Statistics

Use of Statistics in Evidence-Based Practice

Review of Key Research Methodology Concepts and Terms

Frequency Distributions

Graphs and Charts

Measures of Central Tendency

Measures of Dispersion

Types of Distributions

Z-Scores, Percentiles and Effect Size

Probability and Sampling Distributions

Hypothesis Testing and Statistical Significance

Type I and Type Ii Errors

Interpreting the Strength and Importance of Relationships

Analysis of Variance

Cross Tabulation and Chi-Square

Correlation

Regression Analysis

Applications to Single-System Evaluation Designs

Filters

Exam 14: The T-Test

An independent samples t -Test with a sample size of 50 will have 48 degrees of freedom.

The term degrees of freedom refers to how many values are free to vary in a set of values if we know the summary statistic and the number of values in the set.

In a pilot study, Dana wants to test the significance of the improvement in mean scores from pretest to posttest.Dana should use:

When using an independent-samples t-Test, which of the following is considered when calculating the degrees of freedom?

The t-Test formula involves calculating a t-score by:

It is appropriate to use the independent-samples t-Test when:

It is appropriate to use the t-Test when:

It is appropriate to use the paired-samples t-Test when:

A t distribution will provide a better estimate of the population mean and standard error than will a z distribution when the sample size is very small or badly skewed.

An independent samples t -Test with a sample size of 100 will have 2 degrees of freedom.

The paired-samples t-Test is used when the two groups of values that we want to compare are connected or related to each other in some way.

If one group has a significant change in a paired-samples t-Test, and another group does not in its (separate) paired-samples t-Test, that signifies a significant difference between the groups.

A non-parametric alternative to the t -Test can be used when dependent variable is at the ordinal level of measurement or is not distributed normally.

Suppose a study is done in which the experimental and control groups both get pretests and posttests.Which of the following is the best statistical procedure?

The t -Test calculates a t-score by dividing the difference between two means by the standard error of the difference between means in the theoretical sampling distribution.

It is appropriate to use the t-Test when:

The independent-samples t-Test is used when we want to compare the means of two independent groups.

Suppose an experiment compares two independent groups on an ordinal dependent variable.Which of the following is the most appropriate nonparametric statistical procedure

All t -Tests use the same t distribution regardless of the size of the sample and its standard deviation.

Why Study Statistics

Use of Statistics in Evidence-Based Practice

Review of Key Research Methodology Concepts and Terms

Frequency Distributions

Graphs and Charts

Measures of Central Tendency

Measures of Dispersion

Types of Distributions

Z-Scores, Percentiles and Effect Size

Probability and Sampling Distributions

Hypothesis Testing and Statistical Significance

Type I and Type Ii Errors

Interpreting the Strength and Importance of Relationships

Analysis of Variance

Cross Tabulation and Chi-Square

Correlation

Regression Analysis

Applications to Single-System Evaluation Designs

Filters