Question 1

The total variability in the dependent variable,as represented by SSTOTAL,can be spilt up,or partitioned,into two components:

Accepted Answer

A) SSEXPLAINED + SSERROR 
B) SSUNEXPLAINED + SSERROR 
C) SSEXPLAINED + SSIV 
D) none of these 
A) SSEXPLAINED + SSERROR 
B) SSUNEXPLAINED + SSERROR 
C) SSEXPLAINED + SSIV 
D) none of these

Question 2

Explained variance is variability associated with (explained by)disturbance variables.

Accepted Answer

A) True 
 B)False

Question 3

Before a researcher decides what statistical test,and if an independent t-test is correct he/ she must determine_____.

Accepted Answer

A) The number of independent variables manipulated 
B) Scale of measurement of the dependent variable (quantitative vs.qualitative) 
C) Within or between subject design 
D) The number of subjects used 
E) All of these are correct 
A) The number of independent variables manipulated 
B) Scale of measurement of the dependent variable (quantitative vs.qualitative) 
C) Within or between subject design 
D) The number of subjects used 
E) All of these are correct

Question 4

The mean of a sampling distribution of the difference between two independent means is always equal to the:

Accepted Answer

A) difference between the population means 
B) difference between the sample means 
C) standard error of estimate 
D) standard error of the difference 
A) difference between the population means 
B) difference between the sample means 
C) standard error of estimate 
D) standard error of the difference

Question 5

A physical therapist is interested in whether people with different bone structures will be affected differently by her new therapy program.She randomly chooses two groups of patients based on bone type: small-boned frame (XS)and large-boned frame (XL).Patients all had similar injuries.She measures the number of days each person takes to progress to a predetermined point.Here is the data:  
What are the degrees of freedom for the t test for two independent samples?

Accepted Answer

A) 3 
B) 25 
C) 26 
D) 27 
A) 3 
B) 25 
C) 26 
D) 27

Question 6

The mean of a sampling distribution of the differences between two independent means

Accepted Answer

A) always equals zero 
B) always equals one 
C) always equals the difference between the sample means 
D) always equals the difference between the population means 
A) always equals zero 
B) always equals one 
C) always equals the difference between the sample means 
D) always equals the difference between the population means

Question 7

Many properties of a sampling distribution of the mean do not hold for a sampling distribution of the difference between two independent means.

Accepted Answer

A) True 
 B)False

Question 8

The procedure which produces a pooled weighted estimate of the sample variances combines the individual estimates in a manner which is ____.

Accepted Answer

A) proportional to their mean difference 
B) unaffected by sample size 
C) proportional to their degrees of freedom 
D) proportional to the size of difference between the variance estimates 
A) proportional to their mean difference 
B) unaffected by sample size 
C) proportional to their degrees of freedom 
D) proportional to the size of difference between the variance estimates

Question 9

If the sample sizes are not equal,then the pooled variance estimate should be calculated ____.

Accepted Answer

A) using the unweighted mean of the variances 
B) using a weighted mean of the variances 
C) by reducing the size of one group to equal the size of the other group 
A) using the unweighted mean of the variances 
B) using a weighted mean of the variances 
C) by reducing the size of one group to equal the size of the other group

Question 10

In an APA results section and independent groups t-test is written as follows t(82)= 5.66,p<0.05.Based on this information what are the degrees of freedom?

Accepted Answer

A) 5.66 
B) 82 
C) 80 
D) cannot be determined 
A) 5.66 
B) 82 
C) 80 
D) cannot be determined

Question 11

According to the homogeneity of variance assumption:

Accepted Answer

A) ó12 + ó22 = ó2 
B) ó12 = ó22 = ó2 
C) ó12 - ó22 = ó2 
D) ó12 = ó22 + ó2 
A) ó12 + ó22 = ó2 
B) ó12 = ó22 = ó2 
C) ó12 - ó22 = ó2 
D) ó12 = ó22 + ó2

Question 12

When is the independent groups t test used to analyze the relationship between two variables?

Accepted Answer

The independent groups t test is typical

Question 13

Under certain conditions,the independent groups t test is robust to violations of the _____ and _____ assumptions.

Accepted Answer

A) equal n;heterogeneity of variance 
B) randomization;independence 
C) normality;homogeneity of variance 
D) unequal n;normality 
A) equal n;heterogeneity of variance 
B) randomization;independence 
C) normality;homogeneity of variance 
D) unequal n;normality

Question 14

Analogous to the standard error of the mean,the size of the standard error of the difference is influenced by two factors: (1)the sample sizes (n1 and n2)and (2)the variability of scores in the populations (ó12 and ó22).

Accepted Answer

A) True 
 B)False

Question 15

The set of all t values more extreme than the critical values constitute an unexpected result or,more formally,the rejection region.

Accepted Answer

A) True 
 B)False

Question 16

If the researcher suspects that the strength of the relationship between two variables in the population is .45,what sample size should she use per group in a study involving two independent groups and an alpha level of .05,directional test,in order to achieve a power of .85?

Accepted Answer

A) 4 
B) 5 
C) 6 
A) 4 
B) 5 
C) 6

Question 17

Treatment effects are defined as the difference between a given _____ and the _____.

Accepted Answer

A) grand mean;population mean 
B) sample mean;population mean 
C) group mean;grand mean 
D) raw score;group mean 
A) grand mean;population mean 
B) sample mean;population mean 
C) group mean;grand mean 
D) raw score;group mean

Question 18

What are the assumptions of the independent groups t test?

Accepted Answer

The t statistic approximately follows a

Question 19

The sum of squares total represents the total amount of variability that exists in the data.

Accepted Answer

A) True 
 B)False

Question 20

In an APA results section and independent groups t-test is written as follows t(82)= 5.66,p<0.05.Based on this information were the groups significantly different?

Accepted Answer

A) yes,since p<0.05 
B) no,since p should be less than 0.01 to be significant 
C) there may be a type II error 
D) there may not be enough subjects 
A) yes,since p<0.05 
B) no,since p should be less than 0.01 to be significant 
C) there may be a type II error 
D) there may not be enough subjects

The total variability in the dependent variable,as represented by SS_TOTAL,can be spilt up,or partitioned,into two components:

Explained variance is variability associated with (explained by)disturbance variables.

Before a researcher decides what statistical test,and if an independent t-test is correct he/ she must determine_____.

The mean of a sampling distribution of the difference between two independent means is always equal to the:

The mean of a sampling distribution of the differences between two independent means

Many properties of a sampling distribution of the mean do not hold for a sampling distribution of the difference between two independent means.

The procedure which produces a pooled weighted estimate of the sample variances combines the individual estimates in a manner which is ____.

If the sample sizes are not equal,then the pooled variance estimate should be calculated ____.

In an APA results section and independent groups t-test is written as follows t(82)= 5.66,p<0.05.Based on this information what are the degrees of freedom?

According to the homogeneity of variance assumption:

When is the independent groups t test used to analyze the relationship between two variables?

Under certain conditions,the independent groups t test is robust to violations of the _ and _ assumptions.

Analogous to the standard error of the mean,the size of the standard error of the difference is influenced by two factors: (1)the sample sizes (n₁ and n₂)and (2)the variability of scores in the populations (ó₁² and ó₂²).

The set of all t values more extreme than the critical values constitute an unexpected result or,more formally,the rejection region.

If the researcher suspects that the strength of the relationship between two variables in the population is .45,what sample size should she use per group in a study involving two independent groups and an alpha level of .05,directional test,in order to achieve a power of .85?

Treatment effects are defined as the difference between a given _ and the _.

What are the assumptions of the independent groups t test?

The sum of squares total represents the total amount of variability that exists in the data.

In an APA results section and independent groups t-test is written as follows t(82)= 5.66,p<0.05.Based on this information were the groups significantly different?

Introduction and Mathematical Preliminaries

Frequency and Probability Distributions

Measures of Central Tendency and Variability

Percentiles,percentile Ranks,standard Scores,and the Normal Distribution

Pearson Correlation and Regression: Descriptive Aspects

Probability

Estimation and Sampling Distributions

Hypothesis Testing: Inferences About a Single Mean

Principles of Research Design and Statistical Preliminaries for Analyzing Bivariate Relationships

Correlated Groups T-Test

One-Way Repeated Measures Analysis of Variance

Pearson Correlation and Regression: Inferential Aspects

Chi-Square Test

Nonparametric Statistics

Two-Way Between-Subjects Analysis of Variance

Overview and Extension: Statistical Tests for More Complex Designs

Filters

Exam 10: Independent Groups T-Test

The total variability in the dependent variable,as represented by SSTOTAL,can be spilt up,or partitioned,into two components:

Explained variance is variability associated with (explained by)disturbance variables.

Before a researcher decides what statistical test,and if an independent t-test is correct he/ she must determine_____.

The mean of a sampling distribution of the difference between two independent means is always equal to the:

The mean of a sampling distribution of the differences between two independent means

Many properties of a sampling distribution of the mean do not hold for a sampling distribution of the difference between two independent means.

The procedure which produces a pooled weighted estimate of the sample variances combines the individual estimates in a manner which is ____.

If the sample sizes are not equal,then the pooled variance estimate should be calculated ____.

In an APA results section and independent groups t-test is written as follows t(82)= 5.66,p<0.05.Based on this information what are the degrees of freedom?

According to the homogeneity of variance assumption:

When is the independent groups t test used to analyze the relationship between two variables?

Under certain conditions,the independent groups t test is robust to violations of the _____ and _____ assumptions.

Analogous to the standard error of the mean,the size of the standard error of the difference is influenced by two factors: (1)the sample sizes (n1 and n2)and (2)the variability of scores in the populations (ó12 and ó22).

The set of all t values more extreme than the critical values constitute an unexpected result or,more formally,the rejection region.

If the researcher suspects that the strength of the relationship between two variables in the population is .45,what sample size should she use per group in a study involving two independent groups and an alpha level of .05,directional test,in order to achieve a power of .85?

Treatment effects are defined as the difference between a given _____ and the _____.

What are the assumptions of the independent groups t test?

The sum of squares total represents the total amount of variability that exists in the data.

In an APA results section and independent groups t-test is written as follows t(82)= 5.66,p<0.05.Based on this information were the groups significantly different?

Introduction and Mathematical Preliminaries

Frequency and Probability Distributions

Measures of Central Tendency and Variability

Percentiles,percentile Ranks,standard Scores,and the Normal Distribution

Pearson Correlation and Regression: Descriptive Aspects

Probability

Estimation and Sampling Distributions

Hypothesis Testing: Inferences About a Single Mean

Principles of Research Design and Statistical Preliminaries for Analyzing Bivariate Relationships

Correlated Groups T-Test

One-Way Repeated Measures Analysis of Variance

Pearson Correlation and Regression: Inferential Aspects

Chi-Square Test

Nonparametric Statistics

Two-Way Between-Subjects Analysis of Variance

Overview and Extension: Statistical Tests for More Complex Designs

Filters

The total variability in the dependent variable,as represented by SS_TOTAL,can be spilt up,or partitioned,into two components:

Under certain conditions,the independent groups t test is robust to violations of the _ and _ assumptions.

Analogous to the standard error of the mean,the size of the standard error of the difference is influenced by two factors: (1)the sample sizes (n₁ and n₂)and (2)the variability of scores in the populations (ó₁² and ó₂²).

Treatment effects are defined as the difference between a given _ and the _.