Question 1

Groups of participants that are related in some way are known as _________ groups.

Accepted Answer

A)   random
B)   independent
C)   correlated
D)   confounded C

Question 2

In the following study, participants were randomly assigned to receive humanistic therapy, psychodynamic therapy, or behavioral therapy for their depression. Six months after therapy ended, participants' levels of depression were rated on a Likert scale from 1 (not at all depressed) to 15 (extremely depressed).
 $\begin{array}{lcccc}
{\text { GROUP }} & \text { N } & \text { MEAN } & \text { STD DEV } & \text { STD ERROR } \
\text { 1 (humanistic) } & 10 & 5.40 & 2.17 & 0.69 \
\text { 2 (psychodynamic) } & 10 & 7.50 & 2.84 & 0.90 \
\text { 3 (behavioral) } & 10 & 5.60 & 3.13 & 0.99
\end{array}$

ONEWAY ANOVA: THERAPY bY DEPRESSION
$\begin{array} { l c c c c c } & \text { SUM OF } & & \text { MEAN } & & \ \text { SOURCE } & \text { SQUARES } & \text { DF } & \text { SQUARES } & \text { F RATIO } & \text { PROB. } \ & & & & & \ \text { BETWEEN GROUPS } & 26.87 & 2 & 13.73 & 1.78 & .187 \ \text { WTHIN GROUPS } & 203.30 & 27 & 7.53 & & \ \text { TOTAL } & 230.17 & 29 & & & \end{array}$

POST HOC TEST: Tukey-HSD with significance level .05
* Indicates significant differences shown for pairings

$\begin{array}{lll}
G & G & G \
r & r & r \
p & p & p \
1 & 2 & 3
\end{array}$

$\begin{array}{ll}
\text { Mean}& \text { THERAPY }\
5.40 & \text { Grp 1 } \
7.50 & \text { Grp 2 } \
5.60 & \text { Grp 3 }

\end{array}$

-This study is an independent groups design. How do you know?

Accepted Answer

This is an independent groups design because participants were randomly assigned to condition.

Question 3

Briefly describe the three strategies for creating multiple-correlated groups: (1) matched sets, (2) repeated measures, and (3) natural sets.

Accepted Answer

1) Matched sets: This strategy involves creating groups of individuals who are matched on specific characteristics, such as age, gender, or other relevant variables. This ensures that the groups are similar in terms of these characteristics, allowing for comparisons to be made between them.

2) Repeated measures: In this strategy, the same group of individuals is measured multiple times under different conditions or at different time points. This allows for within-subject comparisons and the examination of how variables change over time or in different situations.

3) Natural sets: This strategy involves identifying naturally occurring groups, such as siblings, twins, or members of the same community, and comparing them based on their shared characteristics. This approach allows for the examination of how variables may be influenced by shared environmental or genetic factors within these natural sets.

Question 4

Describe ex post facto research. Give an example of a multiple-group ex post facto study.

Accepted Answer

The answer of Describe ex post facto research. Give an...

Question 5

_________ groups designs have decreased error variability compared to _____________ groups designs.

Accepted Answer

A)   Independent; correlated
B)   Correlated; matched sets
C)   Correlated; independent
D)   Matched sets; correlated

Question 6

Compare and contrast the two-group design and the multiple-group designs. In what ways are they similar? In what ways are they different? Under what circumstances should you choose the multiple-group design over the two-group design? Under what circumstances should you choose the two-group design over the multiple-group design?

Accepted Answer

The answer of Compare and contrast the two-group design and...

Question 7

In the following study, participants were randomly assigned to receive humanistic therapy, psychodynamic therapy, or behavioral therapy for their depression. Six months after therapy ended, participants' levels of depression were rated on a Likert scale from 1 (not at all depressed) to 15 (extremely depressed).
 $\begin{array}{lcccc}
{\text { GROUP }} & \text { N } & \text { MEAN } & \text { STD DEV } & \text { STD ERROR } \
\text { 1 (humanistic) } & 10 & 5.40 & 2.17 & 0.69 \
\text { 2 (psychodynamic) } & 10 & 7.50 & 2.84 & 0.90 \
\text { 3 (behavioral) } & 10 & 5.60 & 3.13 & 0.99
\end{array}$

ONEWAY ANOVA: THERAPY bY DEPRESSION
$\begin{array} { l c c c c c } & \text { SUM OF } & & \text { MEAN } & & \ \text { SOURCE } & \text { SQUARES } & \text { DF } & \text { SQUARES } & \text { F RATIO } & \text { PROB. } \ & & & & & \ \text { BETWEEN GROUPS } & 26.87 & 2 & 13.73 & 1.78 & .187 \ \text { WTHIN GROUPS } & 203.30 & 27 & 7.53 & & \ \text { TOTAL } & 230.17 & 29 & & & \end{array}$

POST HOC TEST: Tukey-HSD with significance level .05
* Indicates significant differences shown for pairings

$\begin{array}{lll}
G & G & G \
r & r & r \
p & p & p \
1 & 2 & 3
\end{array}$

$\begin{array}{ll}
\text { Mean}& \text { THERAPY }\
5.40 & \text { Grp 1 } \
7.50 & \text { Grp 2 } \
5.60 & \text { Grp 3 }

\end{array}$

-What is the dependent variable in this study?

Accepted Answer

The answer of In the following study, participants were randomly...

Question 8

What is the formula for between-groups degrees of freedom?

Accepted Answer

A)   Number of participants - number of groups
B)   Number of groups - number of participants
C)   Number of groups - 1
D)   Number of participants - 1

Question 9

Suppose you find an overall significant F ratio in your one-way ANOVA. What should you do next?

Accepted Answer

A)   Write up your results in APA format.
B)   Conduct a post hoc test to determine which means are significantly different from each other.
C)   Conduct a follow-up study with new participants.
D)   Check the output to make sure the results are asymptotic.

Question 10

Which of the following is NOT a control procedure?

Accepted Answer

A)   Random assignment
B)   Matching
C)   Natural sets
D)   Convenience sampling

Question 11

An experimental effect caused by expectation or suggestion rather than the IV is known as

Accepted Answer

A)   a parsimonious effect.
B)   error variability.
C)   randomization.
D)   a placebo effect.

Question 12

Groups of participants that are formed by random assignment are known as _________ groups.

Accepted Answer

A)   correlated
B)   independent
C)   matched pairs
D)   natural pairs

Question 13

What is a placebo effect? Give an example of a multiple-group experiment in which the researcher tests for a placebo effect (e.g., the coffee example from the text).

Accepted Answer

The answer of What is a placebo effect? Give an...

Question 14

Sum of squares refers to the

Accepted Answer

A)   sum of the squared deviations around the mean.
B)   between-groups variability squared.
C)   within-groups variability squared.
D)   sum of the squared means.

Question 15

Questions refer to Table 11-2. In this study, 10 children completed a survey regarding their impressions of smokers at age 8 and then again at age 10 and 12. Scores could range from 1 (extreme negative impression of smokers) to 20 (extreme positive impression of smokers).

Table 11-2
$\begin{array} { c c c c c } \text { GROUP } & \mathrm { N } & \text { MEAN } & \text { STD DEV } & \text { STD ERROR } \ 1 \text { (AGE 8) } & 10 & 9.70 & 5.89 & 1.86 \ 2 \text { (AGE 10) } & 10 & 10.40 & 5.58 & 1.76 \ 3 \text { (AGE 12) } & 10 & 11.80 & 5.94 & 1.88 \end{array}$

ONEWAY ANOVA: SMOKING by AGE (CORR SAMP)

$\begin{array} { l c c c r r }

& \text { SUM OF } & \text { MEAN } & & \ \text { SOURCE } & \text { SQUARES } & \text { DF } & \text { SQUARES } & \text { F RATIO } & \text { PROB. } \ 
\text { AGE } & 22.87 & 2 & 11.43 & 6.76 & .006 \
\text { SUBJECTS } & 879.63 & 9 & 97.74 & 34.71 & .000 \
\text { WITHIN CELLS } & 30.47 & 18 & 1.69 & & \
\text { TOTAL } & 932.97 & 29 & & &
 \end{array}$

POST HOC TEST: Tukey-HSD with significance level .05
* Indicates significant differences shown for pairings
$\begin{array} { l l l } \mathrm { G } & \mathrm { G } & \mathrm { G } \ \mathrm { r } & \mathrm { r } & \mathrm { r } \ \mathrm { p } & \mathrm { p } & \mathrm { p } \ 1 & 2 & 3 \end{array}$

$\begin{array}{ll}
\text { Mean } & \mathrm{AGE}\

9.70 & \text { Grp } 1 \
10.40 & \text { Grp 2 } \
11.80 & \text { Grp } 3

\end{array}$
-Consult Table 11-1. The p-value is ______ than .05; therefore, the results of the statistical analysis _____ significant.

Accepted Answer

A)   greater; are
B)   greater; are not
C)   less; are
D)   less; are not

Question 16

A researcher was interested in determining the effectiveness of humanistic therapy for alleviating depression. He administered a depression inventory to a sample of clients with depression on three occasions: before therapy started, two months after therapy began, and four months into therapy. Depression scores could range from 1 (not at all depressed) to 15 (extremely depressed).
 $\begin{array}{ccccc}
\text { GROUP } & \mathrm{N} & \text { MEAN } & \text { STD DEV } & \text { STD ERROR } \
1 \text { (Time 1) } & 10 & 13.50 & 1.58 & 0.50 \
2 \text { (Time 2) } & 10 & 9.40 & 2.88 & 0.91 \
3 \text { (Time 3) } & 10 & 7.30 & 4.06 & 1.28
\end{array}$

$\text { ONEWAY ANOVA: DEPRESSION by TIME (CORR SAMP) }$

$\begin{array}{lrrrrr} 
& \text { SUM OF } &&  {\text { MEAN }} \
\text { SOURCE } & \text { SQUARES } & \text { DF } & \text { SQUARES } & \text { F RATIO } & \text { PROB. } \
\text { TIME } & 198.87 & 2 & 99.43 & 18.43 & .000 \
\text { SUBJECTS } & 147.88 & 9 & 16.43 & 185.04 & .000 \
\text { WITHIN CELLS } & 97.13 & 18 & 5.40 & & \
\text { TOTAL } & 443.88 & 29 & & &
\end{array}$

POST HOC TEST: Tukey-HSD with significance level .05
* Indicates significant differences shown for pairings

$\begin{array}{lll}
G & G & G \
r & r & r \
p & p & p \
1 & 2 & 3
\end{array}$

$\begin{array}{ll}
\text { Mean}&\text { TIME }\

13.50 & \text { Grp } 1 \
9.40 & \text { Grp 2 } \
7.30 & \text { Grp 3 }

\end{array}$

-Is this a two-group design or a multiple-group design? How do you know?

Accepted Answer

The answer of A researcher was interested in determining the...

Question 17

When you use _________, each participant must take place in all the various treatment conditions.

Accepted Answer

A)   matched sets
B)   natural sets
C)   repeated measures
D)   random assignment

Question 18

Hugh conducts an experiment with three independent groups and 20 participants in each group. The between-groups degrees of freedom would equal

Accepted Answer

A)   2
B)   3
C)   23
D)   57

Question 19

Darryl conducts a study in which participants rate their liking for their professor on the first day of class, at midterm, and on the last day of class. Darryl has used which research design?

Accepted Answer

A)   Matched sets
B)   Natural sets
C)   Independent groups
D)   Repeated measures

Question 20

Questions refer to Table 11-2. In this study, 10 children completed a survey regarding their impressions of smokers at age 8 and then again at age 10 and 12. Scores could range from 1 (extreme negative impression of smokers) to 20 (extreme positive impression of smokers).

Table 11-2
$\begin{array} { c c c c c } \text { GROUP } & \mathrm { N } & \text { MEAN } & \text { STD DEV } & \text { STD ERROR } \ 1 \text { (AGE 8) } & 10 & 9.70 & 5.89 & 1.86 \ 2 \text { (AGE 10) } & 10 & 10.40 & 5.58 & 1.76 \ 3 \text { (AGE 12) } & 10 & 11.80 & 5.94 & 1.88 \end{array}$

ONEWAY ANOVA: SMOKING by AGE (CORR SAMP)

$\begin{array} { l c c c r r }

& \text { SUM OF } & \text { MEAN } & & \ \text { SOURCE } & \text { SQUARES } & \text { DF } & \text { SQUARES } & \text { F RATIO } & \text { PROB. } \ 
\text { AGE } & 22.87 & 2 & 11.43 & 6.76 & .006 \
\text { SUBJECTS } & 879.63 & 9 & 97.74 & 34.71 & .000 \
\text { WITHIN CELLS } & 30.47 & 18 & 1.69 & & \
\text { TOTAL } & 932.97 & 29 & & &
 \end{array}$

POST HOC TEST: Tukey-HSD with significance level .05
* Indicates significant differences shown for pairings
$\begin{array} { l l l } \mathrm { G } & \mathrm { G } & \mathrm { G } \ \mathrm { r } & \mathrm { r } & \mathrm { r } \ \mathrm { p } & \mathrm { p } & \mathrm { p } \ 1 & 2 & 3 \end{array}$

$\begin{array}{ll}
\text { Mean } & \mathrm{AGE}\

9.70 & \text { Grp } 1 \
10.40 & \text { Grp 2 } \
11.80 & \text { Grp } 3

\end{array}$
-Consult Table 11-1. Which means are significantly different from each other?

Accepted Answer

A)   The high dose group is significantly different from the low dose group, and no other comparisons are significant.
B)   The high dose group is significantly different from the no dose group and the low dose group, and the low dose group and the no dose group do not significantly differ from each other.
C)   The high dose group and the low dose group are significantly different from the no dose group, and the high dose and low dose group do not significantly differ from each other.
D)   All three groups are significantly different from each other.

Exam 11: Designing, Conducting, Analyzing, and Interpreting Experiments With More Than Two Groups

Groups of participants that are related in some way are known as _________ groups.

Briefly describe the three strategies for creating multiple-correlated groups: (1) matched sets, (2) repeated measures, and (3) natural sets.

Describe ex post facto research. Give an example of a multiple-group ex post facto study.

_ groups designs have decreased error variability compared to _____ groups designs.

What is the formula for between-groups degrees of freedom?

Suppose you find an overall significant F ratio in your one-way ANOVA. What should you do next?

Which of the following is NOT a control procedure?

An experimental effect caused by expectation or suggestion rather than the IV is known as

Groups of participants that are formed by random assignment are known as _________ groups.

What is a placebo effect? Give an example of a multiple-group experiment in which the researcher tests for a placebo effect (e.g., the coffee example from the text).

Sum of squares refers to the

When you use _________, each participant must take place in all the various treatment conditions.

Hugh conducts an experiment with three independent groups and 20 participants in each group. The between-groups degrees of freedom would equal

Darryl conducts a study in which participants rate their liking for their professor on the first day of class, at midterm, and on the last day of class. Darryl has used which research design?