Question 1

Post hoc tests are frequently carried out after the null hypothesis has been rejected in an ANOVA.

Accepted Answer

A) True 
 B)False

Question 2

According to Cohen's conventions, an R2 of 0.15 is considered to be a(n) _____ effect size.

Accepted Answer

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

Question 3

When the F statistic is more than the critical cutoff value, additional follow-up analyses are needed.

Accepted Answer

A) True 
 B)False

Question 4

Tilbe wants to compare young children's verbal test scores across three experimental conditions (different levels of instruction from low to high) and one control group (no instruction).What type of test should she use?

Accepted Answer

A)  z test 
B)  t test 
C)  Bonferroni test 
D)  ANOVA

Question 5

If the cutoff q statistic is 4.96, with a p level of 0.05, which of these would be significant?

Accepted Answer

A)  an HSD of 4.8 
B)  a group mean difference of 5.2 
C)  an F of 5.2 
D)  an HSD of 5.2

Question 6

In which situation would it be necessary to use a within-groups ANOVA?

Accepted Answer

A)  A researcher is interested in a longitudinal study that follows a group of kindergarten children through high school and assesses their body mass index at four time points. 
B)  A researcher classifies a group of college students on the basis of their political leanings as liberal, conservative, libertarian, or green. 
C)  A researcher is interested in the effects of distraction on driving performance and randomly assigns participants to one of three distraction groups. 
D)  A researcher is interested in whether a sensitivity training class changes attitudes toward minority populations.The researcher assesses these attitudes before and after the sensitivity training class.

Question 7

The less overlap there is among sample distributions, the:

Accepted Answer

A)  less confounding variability there is in the groups. 
B)  less confident we are that the samples represent true differences in the population. 
C)  more confident we are that the samples represent true differences in the population. 
D)  less likely it is that we will reject the null hypothesis.

Question 8

The proportion of variance in the dependent variable that is accounted for by the independent variable is _____.

Accepted Answer

A)  t 
B)  Cohen's d 
C)  R2 
D)  z

Question 9

An ANOVA is typically used when the dependent variable is nominal with more than two groups.

Accepted Answer

A) True 
 B)False

Question 10

After a researcher _____ the null hypothesis, the researcher should conduct a(n) _____ to determine which means are statistically significantly different from each other.

Accepted Answer

A)  fails to reject; post hoc test 
B)  rejects; post hoc test 
C)  fails to reject; effect size test 
D)  rejects; effect size test

Question 11

As the variability of between-groups means increases, the F statistic increases.

Accepted Answer

A) True 
 B)False

Question 12

R2, the effect size for ANOVA, is calculated as a ratio of:

Accepted Answer

A)  total sum of squares to within-groups sum of squares. 
B)  within-groups mean squares to between-groups mean squares. 
C)  total mean squares to total sum of squares. 
D)  between-groups sums of squares to total sum of squares.

Question 13

The critical cutoffs for a two-tailed Tukey HSD test comparing two group means with 12 within-groups degrees of freedom are:

Accepted Answer

A)  -3.08 and 3.08. 
B)  -3.77 and 3.77. 
C)  -3.82 and 3.82. 
D)  -5.05 and 5.05.

Question 14

An ANOVA is typically used when the independent variable is nominal with more than two groups.

Accepted Answer

A) True 
 B)False

Question 15

Post hoc tests are frequently carried out before the null hypothesis has been rejected in an ANOVA.

Accepted Answer

A) True 
 B)False

Question 16

When the null hypothesis is true, the F ratio for analysis of variance is expected, on average, to be 0.

Accepted Answer

A) True 
 B)False

Question 17

For an F distribution with 3 degrees of freedom between and 32 degrees of freedom within, how many groups are being compared and how many participants are in each group, assuming equal numbers of participants per group?

Accepted Answer

A)  2 groups, 8 participants in each group 
B)  4 groups, 36 participants in each group 
C)  3 groups, 10 participants in each group 
D)  4 groups, 32 participants in each group

Question 18

The z, t, and F distributions have something in common-the denominator of the test statistic:

Accepted Answer

A)  contains a measure of difference among group means. 
B)  contains a measure of difference within the various groups. 
C)  is a squared number. 
D)  represents what would be expected if the null hypothesis were true.

Question 19

The assumptions of ANOVA are that samples are selected:

Accepted Answer

A)  randomly and that the samples come from populations with unequal variances. 
B)  randomly, the population distribution is normal, and the samples come from populations with equal variances. 
C)  randomly and the population distribution is normal. 
D)  from populations that are heteroscedastic and normally distributed.

Question 20

Populations that have different variances are referred to as heteroscedastic.

Accepted Answer

A) True 
 B)False

Exam 12: One-Way Between-Groups Anova

Post hoc tests are frequently carried out after the null hypothesis has been rejected in an ANOVA.

According to Cohen's conventions, an R² of 0.15 is considered to be a(n) _____ effect size.

When the F statistic is more than the critical cutoff value, additional follow-up analyses are needed.

Tilbe wants to compare young children's verbal test scores across three experimental conditions (different levels of instruction from low to high) and one control group (no instruction) .What type of test should she use?

If the cutoff q statistic is 4.96, with a p level of 0.05, which of these would be significant?

In which situation would it be necessary to use a within-groups ANOVA?

The less overlap there is among sample distributions, the:

The proportion of variance in the dependent variable that is accounted for by the independent variable is _____.

An ANOVA is typically used when the dependent variable is nominal with more than two groups.

After a researcher _ the null hypothesis, the researcher should conduct a(n) _ to determine which means are statistically significantly different from each other.

As the variability of between-groups means increases, the F statistic increases.

R², the effect size for ANOVA, is calculated as a ratio of:

The critical cutoffs for a two-tailed Tukey HSD test comparing two group means with 12 within-groups degrees of freedom are:

An ANOVA is typically used when the independent variable is nominal with more than two groups.

Post hoc tests are frequently carried out before the null hypothesis has been rejected in an ANOVA.

When the null hypothesis is true, the F ratio for analysis of variance is expected, on average, to be 0.

For an F distribution with 3 degrees of freedom between and 32 degrees of freedom within, how many groups are being compared and how many participants are in each group, assuming equal numbers of participants per group?

The z, t, and F distributions have something in common-the denominator of the test statistic:

The assumptions of ANOVA are that samples are selected:

Populations that have different variances are referred to as heteroscedastic.