Deck 11: Teafor Two: Tests Between the Means of Different Groups

Question 1

The t test for independent samples assumes which of the following?

A)There was a pre- and post-test.
B)Scores are independent.
C)Scores are related.
D)Mean scores are equal.

Answer 1

Scores are independent.

Question 2

In the t test for independent samples,the actual statistical test is ______.

A)nondirectional
B)unidirectional
C)multidirectional
D)quasidirectional

Answer 2

nondirectional

Question 3

In order to compute the test statistic,or t value,you must first approximate the sample size by calculating the ______.

A)pooled variance
B)standard deviation
C)degrees of freedom
D)mean score

Answer 3

degrees of freedom

Question 4

The t test for independent means is used when each group is tested ______.

A)once or twice
B)only twice
C)only once
D)any number of times

Question 5

In the formula that computes a t value,what does s₁² represent?

A)scores for Group 1
B)mean for Group 1
C)number of participants for Group 1
D)variance for Group 1

Question 6

Independent groups are ______.

A)not related in any way
B)related to each other
C)dependent on each other
D)continuous

Question 7

The t test for independent means is used when you are testing how many groups?

A)only two groups in total
B)only one group
C)two groups or more
D)one group or more

Question 8

When examining group difference where no direction of the difference is specified,which of the following is used?

A)two-tailed test
B)one-tailed test
C)directional hypothesis
D)critical value

Question 9

When the obtained value is greater than the critical value,what should you do?

A)Reject the null hypothesis.
B)Accept the null hypothesis.
C)Set a higher p value.
D)Increase the sample.

Question 10

The null hypothesis in an independent-samples t-test would be represented as follows:

A)H_0: $\mu$ ₁= $\mu$ ₂
B)H_0: $\mu$ ₁ $\gt$$\mu$ ₂
C)H_0: X₁ = X₂
D)H_1: X₁ = X₂

Question 11

The t test for independent means is used when looking at the difference in average scores of one or more variables between ______ group(s)that are ______ one another.

A)two;dependent on
B)two;independent of
C)one;dependent on
D)one;independent of

Question 12

In order to determine whether you will reject the null hypothesis,the test statistic must be compared against the ______.

A)critical value
B)significance level
C)obtained value
D)p value

Question 13

In the formula that computes a t value,what does n₁ represent?

A)scores for Group 1
B)means for Group 1
C)number of participants for Group 1
D)variance for Group 1

Question 14

The SPSS output for an independent-samples t-test includes all but which of the following?

A)correlation coefficient
B)standard deviation
C)variance
D)mean

Question 15

To examine the difference among the average scores of three unrelated groups,which of the following statistical techniques should be selected?

A)regression
B)dependent-samples t-test
C)independent-samples t-test
D)analysis of variance

Question 16

The research hypothesis in an independent-samples t-test would be represented as follows:

A)H_0: X₁ = X₂
B)H_1: $\mu$ ₁= $\mu$ ₂
C)H_{1: 1} > ₂
D) H_0: $\mu$ ₁= $\mu$ ₂

Question 17

In the formula that computes a t value,what does represent?

A)the number of participants in Group 1
B)the variance for Group 1
C)the mean for Group 1
D)the standard deviation for Group 1

Question 18

The test statistic calculated by the statistical procedure selected is known as the ______.

A)critical value
B)significance level
C)obtained value
D)p value

Question 19

Which of the following is a major assumption of the t test regarding the amount of variability in each group?

A)variables normally distributed
B)sample chosen at random
C)scores are independent
D)variances are equal

Question 20

When examining group difference where the direction of the difference is specified,which of the following is used?

A)two-tailed test
B)one-tailed test
C)directional hypothesis
D)critical value

Question 21

What is the t statistic value also known as?

A)critical value
B)degrees of freedom
C)obtained value
D)test computation

Question 22

What does the number 2.001 represent in the following: t₍₅₈₎= 2.001,p < 0.05?

A)test statistic
B)t value
C)degrees of freedom
D)significance level

Question 23

If there is a significant difference between the distributions of scores in two groups with effect size at .37,how big are the differences between the two groups?

A)no difference
B)medium
C)small
D)large

Question 24

How many groups are involved in the t test for independent samples?

A)one
B)two
C)more than three
D)any number of groups

Question 25

If there is no difference between the distributions of scores in two groups,what is the effect size equal to?

A)20
B)5
C)1
D)0

Question 26

The term for the assumption that the amount of variability in each of the two groups is equal is ______.

A)heterogeneity of variances
B)homogeneity of variance
C)equality of variance
D)stability of variance

Question 27

If the obtained value is less than the critical value,what should you do?

A)Reject the null hypothesis.
B)Accept the null hypothesis.
C)Set a higher p value.
D)Increase the sample.

Question 28

If the obtained t value is 7.14,and the critical value is 6.10,what decision should be made?

A)Accept the null hypothesis.
B)Reject the null hypothesis.
C)Rerun the analysis.
D)Use a one-tailed test.

Question 29

What does the letter t represent in the following: t₍₅₈₎= 2.001,p < 0.05?

A)test statistic
B)t value
C)degrees of freedom
D)significance level

Question 30

What is a small effect for Cohen's d?

A)0.17
B)-0.02
C)0.25
D)0.57

Question 31

What does the number 0.05 represent in the following: t₍₅₈₎= 2.001,p < 0.05?

A)test statistic
B)t value
C)degrees of freedom
D)significance level

Question 32

If the number of participants in Group 1 = 32 and the number in Group 2 = 30,what is the associated degrees of freedom?

A)58
B)59
C)60
D)62

Question 33

When computing effect size,the sample size is ______.

A)used in the denominator
B)not considered
C)used in the numerator
D)sometimes considered

Question 34

Which of the following is the formula used to calculate degrees of freedom for a t test?

A)n₁ - 1 + n₂ - 1
B)n₁ + n₂ - 1
C)n₁ - 1 + n₂
D)n₁ + n₂

Question 35

A measure of the magnitude of the difference between two groups is _____.

A)effect size
B)significance level
C)error size
D)effect size.

Question 36

What does the number 58 represent in the following: t₍₅₈₎= 2.001,p < 0.05?

A)test statistic
B)t value
C)degrees of freedom
D)significance level

Question 37

A researcher wants to create an intervention to improve the well-being of first-semester graduate students,so she gives the professional school counseling students specific doses of rocky road ice cream and the mental health counseling students specific doses of licorice.To analyze the differences in well-being,she would use a(n)______.

A)dependent-samples t test
B)analysis of variance
C)independent-samples t test
D)repeated-measures analysis of variance

Question 38

What is the most common level of significance used in testing in the social sciences?

A)0.05
B)0.01
C)0.001
D)0.10

Question 39

When it comes to significance testing,the level of risk is ______.

A)determined by sample size
B)always set at 0.05
C)set by the researcher
D)irrelevant for t-test

Question 40

If the number of participants in Group 1 = 54 and the number in Group 2 = 58,what is the associated degrees of freedom?

A)99
B)111
C)112
D)110

Question 41

There is an important difference between a significant result and a meaningful result.

Question 42

Effect size is a value that approximates the sample size and is a component of many statistical tests.

Question 43

What does the number 42 represent in the following: t₍₄₂₎= 5.15,p < 0.01?

A)test statistic
B)t value
C)degrees of freedom
D)significance level

Question 44

What does the symbol p represent in the following: t₍₄₂₎= 5.15,p < 0.01?

A)test statistic
B)t value
C)degrees of freedom
D)probability

Question 45

The homogeneity-of-variance,an assumption underlying the t test,states that the amount of variability in both groups is equal.

Question 46

Pooled standard deviation,part of the formula for the Cohen's d effect size,is similar to an average of the standard deviations from both groups.

Question 47

A larger effect size represents a greater difference between the two groups.

Question 48

A researcher wants to study the impact of pizza consumption on the happiness of college freshmen,sophomores,and juniors.What test statistic would the researcher need to use to evaluate the difference in effectiveness between the groups?

A)dependent-samples t-test
B)analysis of variance
C)independent-samples t-test
D)repeated-measures analysis of variance

Question 49

What does the number 5.15 represent in the following: t₍₄₂₎= 5.15,p < 0.01?

A)test statistic
B)t value
C)degrees of freedom
D)probability

Question 50

What does the symbol t represent in the following: t₍₄₂₎= 5.15,p < 0.01?

A)test statistic
B)t value
C)degrees of freedom
D)probability

Question 51

If the effect size is 0.37,what is your interpretation of the group difference?

A)large
B)small
C)weak
D)medium

Question 52

Based on the equation: t₍₄₂₎= 5.15,p < 0.01,what is the right choice in the following?

A)group 1= 21;group 2= 21
B)group 1= 22;group 2= 22
C)group 1= 20;group 2= 20
D)group 1=23;group 2= 23

Question 53

In the effect size formula,what does X₁ bar stand for?

A)the mean for Group 1
B)effect size
C)standard deviation
D)variance for Group 1

Question 54

Effect size is the magnitude of the differences between groups.

Question 55

The test for independent samples should be used when participants are tested multiple times.

Question 56

The sign of the observed t value (i.e. ,whether it is positive or negative)is a crucial element in conducting the t test for independent samples.

Question 57

What does the number 0.01 represent in the following: t₍₄₂₎= 5.15,p < 0.01?

A)test statistic
B)t value
C)degrees of freedom
D)significance level

Question 58

A t test is conducted to detect differences between two groups in which participants are tested only once.

Question 59

In the effect size formula,what does s stand for?

A)standard error of mean
B)effect size
C)standard deviation
D)variance

Question 60

In the effect size formula,what does ES stand for?

A)standard error of mean
B)effect size
C)standard deviation
D)estimated sample size

Question 61

A researcher is testing a two-tailed null hypothesis at the p < 0.01 level with df = 48.What critical value would she or he use? Justify your answer.

Question 62

What are you assuming when you use the simple formula for effect size?

Question 63

If you have a sample size of 500,should you interpret the statistical significance or the effect size?

Question 64

Please identify the elements of the formula for an independent-means t test.

Question 65

Why do we calculate effect size?

Question 66

Under what conditions would a researcher choose to use a t test for independent samples?

Question 67

What does t₍₄₇₎ = 0.23 mean?

Question 68

What is the simplest way to compute an effect size?

Question 69

Under what circumstances would a researcher reject the null hypothesis?