stats chapter 11

A researcher compares differences in positivity between participants in a low-, middle-, or upper middle-class family. If she observes 15 participants in each group, then what are the degrees of freedom for the one-way between-subjects ANOVA?

(2, 42)

A researcher conducts a study in which k = 4 and n = 22 in each group. What are the degrees of freedom for the one-way between-subjects ANOVA?

(3, 84)

A researcher computes a one-way within-subjects ANOVA for a study in which participants are observed across five groups. If the degrees of freedom error is 56, then how many participants were observed in this study?

15

How many sources of error are present in a one-way within-subjects ANOVA?

2

What is the minimum number of groups that can be observed using the one-way between-subjects ANOVA design?

2

A researcher observed the mating behavior of 10 porpoises in 5 different social conditions. What are the degrees of freedom between-groups for a one-way within-subjects ANOVA?

4

Which of the following post hoc tests is associated with the least power to detect an effect?

Tukey's HSD test

A researcher conducts a within-subjects design and notes that scores increased at each level of the factor for all participants. Based on this description, does this test have high power to detect the effect?

Yes, because participant responding was consistent.

Following a significant one-way between-subjects ANOVA in which k > 2, what is the next appropriate step?

conduct post hoc tests

Which measure of proportion of variance tends to overestimate the size of an effect in a population?

eta-squared

Using a within-subjects ANOVA design, ______.

n participants are observed k times

Using a between-subjects ANOVA design, ______.

n · k participants are each observed one time

For an analysis of variance, the term "one-way" refers to ______.

the number of factors in the design

Computing a one-way within-subjects ANOVA is appropriate when ______.

the same participants are observed across groups

The following is a summary of a one-way between-subjects ANOVA: F(2, 37) = 3.42, p < .05, = .12. How many participants were observed in this study?

40

A researcher measures anxiety levels among participants in the presence and absence of a fearful stimulus. If the same participants are observed in each group, then what type of statistical design is appropriate for this study?

both A and C

Computing a one-way between-subjects ANOVA is appropriate when ______.

different participants are observed one time in each of two or more groups for one factor

Which of the following is an assumption for the one-way within-subjects ANOVA, but not for the one-way between-subjects ANOVA?

homogeneity of covariance

"Within-subjects" is also called ______.

repeated-measures

ANOVA stands for ______.

analysis of variance

A researcher notes that the variability attributed to difference between group means is quite large. Which source of variation is the researcher referring to?

between-groups

A researcher observes the same participants in each of five different settings. Which source of variation is the variability attributed to observing the same participants across all five settings?

between-persons variability

Without changing the value of error variance, the ______ the between-groups variability, the more likely we are to reject the null hypothesis.

larger

The following result is reported for a one-way within-subjects ANOVA: F(2, 27) = 3.20, p < .05 ( = .14). Which value in the summary suggests that the design was within-subjects?

the partial estimate for eta-squared

A researcher recorded the shooting percentage of 28 professional basketball players in each of 4 quarters in a game. What are the degrees of freedom error for a one-way within-subjects ANOVA?

81

Which of the following is not a post hoc test for a one-way between-subjects ANOVA?

Which of the following is not a post hoc test for a one-way between-subjects ANOVA?

A professor compared differences in class grades between students in their freshman, sophomore, junior, and senior years of college. If different participants were in each group, then what type of statistical design is appropriate for this study?

a one-way between-subjects ANOVA

Which of the following is a measure of proportion of variance for a one-way between-subjects ANOVA?

both A and B

Which of the following statements is the appropriate way to read the degrees of freedom for an ANOVA with 10 participants in each of four groups?

3 and 36 degrees of freedom

Which of the following post hoc tests is associated with the greatest power to detect an effect?

Fisher's LSD test

A researcher conducts two studies using the one-way between-subjects ANOVA. The sum of squares between groups is smaller in Study 1 than in Study 2; the sum of squares total is the same in both studies. Using eta-squared, in which study will the effect size be larger?

Study 2

Which of the following is a source of variation that is measured using the one-way within-subjects ANOVA?

all of these Answers:a. between-groups variationb. within-groups variationc. between-persons variation

Which source of variation is computed using a one-way within-subjects ANOVA, but not a one-way between-subjects ANOVA?

between-persons variation

Without changing the value of error variance, the ______ the between-groups variability, the more likely we are to retain the null hypothesis

smaller

A researcher conducts two studies using the one-way between-subjects ANOVA. The sum of squares between groups is larger in Study 1 than in Study 2; the sum of squares total is smaller in Study 1 than in Study 2. Using eta-squared, in which study will the effect size be larger?

study 1

In a study with 4 groups and 10 participants in each group, the sum of squares for the between-groups source of variation is 60. What is the value for the mean square between-groups in this study?

20

A researcher measures attractiveness ratings of a male confederate among 30 women who were told the confederate was either single, dating, or married (n = 10 per group). What are the degrees of freedom for error for the one-way between-subjects ANOVA?

27

A researcher computes a one-way within-subjects ANOVA using a sample of eight participants. If the degrees of freedom error is 14, then how many groups were included in this study?

3

The following is a summary of a one-way between-subjects ANOVA: F(2, 37) = 3.42, p < .05, = .12. How many pairwise comparisons need to be made for this ANOVA result?

3

A researcher computes a one-way within-subjects ANOVA in which k = 3 and n = 10. What is the critical value for this test at a .05 level of significance?

3.55`

Which of the following post hoc tests uses the t critical value in the calculation to determine the critical value for the test?

Fisher's LSD test

A researcher divides participants into groups that will engage in low, moderate, or intense levels of exercise. The total calories consumed by participants following the exercise are then recorded. What type of statistical design is appropriate for this study?

a one-way between-subjects ANOVA

The degrees of freedom for error is called ______.

all of these Answers:a. degrees of freedom errorb. degrees of freedom denominatorc. degrees of freedom within-groups

A lowercase k is used to denote ______ using a one-way ANOVA.

both A and C

The degrees of freedom for the between-groups variability is called ______.

both A and C

Post hoc tests are computed ______.

following a significant ANOVA test to make pairwise comparisons

A one-way within-subjects ANOVA is typically associated with ______ power than the one-way between-subjects ANOVA.

larger

A researcher assigned participants (n = 8 per group) to read vignettes describing a person engaging in either a helpful, hurtful, or neutral act. Different participants were assigned to each group and asked to rate how positively they viewed the person described in the vignette. What is the critical value for the one-way between-subjects ANOVA at a .05 level of significance?

3.47

A researcher conducts two studies. In Study 1, she recorded the amount consumed (in calories) among 8 participants observed at 3 meal times (breakfast, lunch, and dinner). In Study 2, she conducted the same study, except that n = 12 participants observed at each of 3 meal times. Which study is associated with a larger value for degrees of freedom between-groups for a one-way within-subjects ANOVA?

The degrees of freedom between-groups are the same in each study

A sex therapist has adult female clients rate their level of interest in each of six relationship situations. To analyze differences in the ratings, what type of statistical design is appropriate for this study?

a one-way within-subjects ANOVA

To summarize a one-way within-subjects ANOVA, we report each of the following except, ______.

the critical values

The source of variability associated with error variance in the one-way between-subjects ANOVA is called ______.

within-groups variability

Which of the following designs are associated with greater power to detect an effect, particularly when there is consistent participant responding between groups?

within-subjects design

A researcher conducts a study using the one-way between-subjects ANOVA. He computes = 120 and = 200. What is the effect size for this test using eta-squared?

.38

A researcher conducts a study in which k = 5 and N = 80. What are the degrees of freedom between-groups for the one-way between-subjects ANOVA?

4

A researcher measures the time it takes eight participants to complete three successive tasks. What are the degrees of freedom between-persons for a one-way within-subjects ANOVA?

7

How does omega-squared for the one-way between-subjects ANOVA correct for the fact that eta-squared tends to be a biased estimate of effect size?

all of these Answers:a. It corrects for the size of error by including in the formula.b. It includes the degrees of freedom between groups () in the formula.c. It accounts for the number of groups that were observed.

Which of the following is an assumption for computing a one-way between-subjects ANOVA?

all of these (The population being sampled from is normally distributed.b. Participants were selected to participate using a random procedure.c. One observation has no effect on the likelihood of another observation)

For the one-way within-subjects ANOVA, the more ______ participant responding between groups, the less powerful the test will be at detecting an effect.

inconsistent

The term "between-subjects" refers to ______.

observing different participants one time in each group

A researcher records depression scores for 12 patients in each of 4 seasons. If depression scores for the same participants are recorded in each season, then what type of statistical design is most appropriate for this study?

one-way within-subjects ANOVA

Partial estimates of effect size make the denominator ______ because the between-persons variability is removed.

smaller

In a study with 3 groups and 13 participants in each group, the sum of squares for the within-groups source of variation is 18. What is the value for the mean square within-groups in this study?

0.5

The source of variation that is associated with differences between groups in a study is called ______.

. between-groups variability

A researcher conducts a study in which k = 6 and n = 6 per group. What are the critical values for the one-way between-subjects ANOVA at a .05 level of significance?

2.53

A researcher computes a one-way within-subjects ANOVA in which k = 4 and n = 20. What are the degrees of freedom error for this test?

57

Which of the following is an assumption for computing a one-way within-subjects ANOVA?

Independent observations were made within groups, but not between groups

When the variability attributed to between-groups is equal to the variability attributed to error, then the value of the test statistic for a one-way between-subjects ANOVA is ______.

equal to 1

The term "within-subjects" refers to ______.

observing the same participants in each group

Homogeneity of variance is an assumption for the one-way between-subjects ANOVA. What does this assumption mean?

that the variance is equal in each population from which samples are selected