Deck 11: Tea for Two: Tests Between the Means of Different Groups

Question 1

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

Answer 1

C

Question 2

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

Answer 2

B

Question 3

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

A) $$H _ { 0 } : \mu _ { 1 } = \mu _ { 2 }$$
B) $$H _ { 1 } : \bar { X } _ { 1 } \neq \bar { X } _ { 1 }$$
C) $$H _ { 0 } : \bar { X } _ { 1 } \neq \bar { X } _ { 1 }$$
D) $$H _ { 1 } : \mu _ { 1 } = \mu _ { 1 }$$

Answer 3

$$H _ { 0 } : \mu _ { 1 } = \mu _ { 2 }$$

Question 4

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

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

Question 5

In the formula that computes a t value, what does 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

In order to determine whether or not 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 7

If 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 8

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 9

Which major assumption of the t-test deals with 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 10

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

A)two, dependent
B)two, independent
C)one, dependent
D)one, independent

Question 11

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 12

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 13

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

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

Question 14

The t-test for independent means is used when there is/are _______.

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

Question 15

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

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

Question 16

If you want to examine the difference among the average scores of three unrelated groups, which of the following statistical techniques should you select?

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

Question 17

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

A) $$H _ { 0 } : \mu _ { 1 } = \mu _ { 1 }$$
B) $$H _ { 0 } : \bar { X } _ { 1 } \neq \bar { X }$$
C) $$H _ { 1 } : \bar { X } _ { 1 } \neq \bar { X } _ { 2 }$$
D) $$H _ { 1 } : \mu _ { 1 } = \mu _ { 1 }$$

Question 18

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

Question 19

The SPSS output for an independent-samples t-test includes all of the following EXCEPT this:

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

Question 20

Independent means that the groups are _______.

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

Question 21

If your obtained t value is 7.14, and the critical value is 6.10, what decision should you make?

A)accept the null hypothesis
B)reject the null hypothesis
C)rerun the analysis
D)use a one-tailed test

Question 22

The t-test for independent samples involves how many groups?

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

Question 23

What does the number 58 represent in the following: t₍₅₈₎ = 2.001, p < .05?

A)Test statistic
B)t value
C)Degrees of freedom
D)Significance level

Question 24

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 25

What does the number .05 represent in the following: t₍₅₈₎ = 2.001, p < .05?

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

Question 26

What 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 27

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 28

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

A)determined by sample size
B)always set at .05
C)set by the researcher
D)irrelevant for t-test

Question 29

The t statistic value is also called the _______.

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

Question 30

When it comes to significance testing in social science, which level of risk is most commonly used?

A).05
B).01
C).001
D).10

Question 31

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 32

What does the number 2.001 represent in the following: t₍₅₈₎ = 2.001, p < .05?

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

Question 33

A measure of how different two groups are from one another in their magnitude is the _______.

A)error size
B)significance level
C)effect size
D)mean score

Question 34

What is the assumption that the amount of variability in each of the two groups is equal?

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

Question 35

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 36

When computing effect size, the sample size is ______.

A)used in the denominator
B)not taken into account
C)used in the numerator
D)sometimes taken into account

Question 37

If there is 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
B)small
C)medium
D)large

Question 38

What is considered to be a small effect for Cohen's d?

A).17
B)−.02
C).25
D).57

Question 39

What does the letter t represent in the following: t₍₅₈₎ = 2.001, p < .05?

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

Question 40

If there is no difference between the distributions of scores in two groups, your effect size will be equal to _______.

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

Question 41

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 42

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

Question 43

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

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

Question 44

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

Question 45

Based on the equation: t₍₄₂₎ = 5.15, p < .01, what is 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 46

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

Question 47

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

Question 48

What does the symbol t represent in the following: t₍₄₂₎ = 5.15, p < .01?

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

Question 49

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

Question 50

Effect size is the magnitude of the differences between groups.

Question 51

If the effect size is .37, what is your interpretation of the group difference?

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

Question 52

What does the number 42 represent in the following: t₍₄₂₎ = 5.15, p < .01?

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

Question 53

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

Question 54

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

Question 55

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

Question 56

What does the number 5.15 represent in the following: t₍₄₂₎ = 5.15, p < .01?

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

Question 57

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 58

What does the symbol p represent in the following: t₍₄₂₎ = 5.15, p < .01?

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

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

What does the number 0.01 represent in the following: t₍₄₂₎ = 5.15, p < .01?

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

Question 61

Why do we calculate effect size?

Question 62

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

Question 63

What is the simplest way to compute an effect size?

Question 64

What does t₍₄₇₎ = .23 mean?

Question 65

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

Question 66

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

Question 67

Under what circumstances would a researcher reject the null hypothesis?

Question 68

A researcher is testing a two-tailed null hypothesis at the p < .01 level with df = 48.What critical value would she or he use? Justify your answer.

Question 69

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