Question 1

We use _________ assignment whenever there is a relationship between the participants in the groups.

Accepted Answer

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

Question 2

Questions refer to the following computer output in which a researcher compared the GPA of traditional (aged 18-22) and nontraditional (aged 23 or older) students.
Table 10-1
GROUP $1 =$ Aged $18 - 22$
GROUP $2 =$ Aged 23 or older
Variable $=$ Grade point average

$\begin{array} { l c c c c } \text { GROUP } & N & \text { Mean } & S D & \text { Standard Error } \ \text { GROUP 1 } & 15 & 2.95 & 0.556 & 0.143 \ \text { GROUP 2 } & 15 & 3.08 & 0.524 & 0.135 \end{array}$

$F _ { \max }$ test $\quad F = 0.225 \quad p = 0.639$
Equal Variances Assumed
$t = - 0.68 \quad d f = 28 \quad p = 0.509$
Equal Variances Not Assumed
$t = - 0.68 \quad d f = 27.90 \quad p = 0.509$
-Consult Table 10-1. How many participants were in the study?

Accepted Answer

A)  15 
B)  28 
C)  30 
D)  None of the above. 
A)  15 
B)  28 
C)  30 
D)  None of the above.

Question 3

Understanding Experiments with Two Groups - Answer Key
Twenty sets of depressed twins are obtained for a study on the effects of a new antidepressant. In each twin set, one twin is assigned to receive the drug, and the other is designed to receive the placebo. Three months later, depression levels are measured on a scale from 1 (not at all depressed) to 7 (very depressed). The following data was obtained:
 GROUP $1 =$ Received drug
GROUP $2 =$ Received placebo
Variable $=$ Depression level
$\begin{array} { l l l l } \text { GROUP } & N & \text { Mean } & S D \ \text { GROUP 1 } & 10 & 3.21 & 1.035 \ \text { GROUP 2 } & 10 & 5.77 & 1.772 \ t = 5.785 & d f = 9 & p = 0.017 & \text { Cohen's } d = .88 \end{array}$
-What kind of research design was used?

Accepted Answer

The answer of Understanding Experiments with Two Groups - Answer...

Question 4

An experiment in which the experimenter directly manipulates the IV is known as a(n)

Accepted Answer

A)  ex post facto research design. 
B)  participant observation. 
C)  correlational research design. 
D)  true experiment. 
A)  ex post facto research design. 
B)  participant observation. 
C)  correlational research design. 
D)  true experiment.

Question 5

When we test participants more than once, we are using a

Accepted Answer

A)  repeated measures design. 
B)  between-subjects design. 
C)  matched pairs design. 
D)  natural pairs design. 
A)  repeated measures design. 
B)  between-subjects design. 
C)  matched pairs design. 
D)  natural pairs design.

Question 6

Certain dependent variables, such as solving puzzles and completing mazes, are difficult to administer more than once. For these research projects, researchers typically avoid which kind of design?

Accepted Answer

A)  matched pairs 
B)  repeated measures 
C)  between-subjects 
D)  natural pairs 
A)  matched pairs 
B)  repeated measures 
C)  between-subjects 
D)  natural pairs

Question 7

In a ___________ design, participants serve as their own controls.

Accepted Answer

A)  between-subjects 
B)  natural pairs 
C)  repeated measures 
D)  matched pairs 
A)  between-subjects 
B)  natural pairs 
C)  repeated measures 
D)  matched pairs

Question 8

Which of the following represents the general formula for statistical tests?

Accepted Answer

A)  error variability / between-groups variability 
B)  within-groups variability / error variability 
C)  error variability / within-groups variability 
D)  between-groups variability / error variability 
A)  error variability / between-groups variability 
B)  within-groups variability / error variability 
C)  error variability / within-groups variability 
D)  between-groups variability / error variability

Question 9

What is the difference between independent groups and correlated groups?

Accepted Answer

Independent groups and correlated groups

Question 10

Was the treatment effective? How do you know? Specifically discuss the results from page 44 in your answer, explaining which findings were significant and which were not.

Accepted Answer

The t tests showed that after

Question 11

What does it mean when an experiment is confounded? Give an example of a confounded experiment and explain how to make the experiment unconfounded.

Accepted Answer

When an experiment is confounded, it mea

Question 12

Understanding Experiments with Two Groups - Answer Key
Twenty sets of depressed twins are obtained for a study on the effects of a new antidepressant. In each twin set, one twin is assigned to receive the drug, and the other is designed to receive the placebo. Three months later, depression levels are measured on a scale from 1 (not at all depressed) to 7 (very depressed). The following data was obtained:
 GROUP $1 =$ Received drug
GROUP $2 =$ Received placebo
Variable $=$ Depression level
$\begin{array} { l l l l } \text { GROUP } & N & \text { Mean } & S D \ \text { GROUP 1 } & 10 & 3.21 & 1.035 \ \text { GROUP 2 } & 10 & 5.77 & 1.772 \ t = 5.785 & d f = 9 & p = 0.017 & \text { Cohen's } d = .88 \end{array}$
-What kind of statistical analysis was used?

Accepted Answer

correlated

Question 13

Distinguish between between-groups variability and error variability. Explain how these concepts factor into a general statistical formula.

Accepted Answer

Between-groups variability refers to the

Question 14

The belief that explanations should remain simple until the simple explanations are no longer valid is known as the principle of

Accepted Answer

A)  variability. 
B)  parsimony. 
C)  repeated measures. 
D)  independent samples. 
A)  variability. 
B)  parsimony. 
C)  repeated measures. 
D)  independent samples.

Question 15

Random ___________ deals with choosing your research participants, whereas random _________ deals with putting those participants into groups.

Accepted Answer

A)  assignment; selection 
B)  comparison; assignment 
C)  selection; assignment 
D)  selection; comparison 
A)  assignment; selection 
B)  comparison; assignment 
C)  selection; assignment 
D)  selection; comparison

Question 16

The Fmax statistic is used to test the assumption of

Accepted Answer

A)  equality of groups. 
B)  the principle of parsimony. 
C)  non-confounded experiments. 
D)  homogeneity of variance. 
A)  equality of groups. 
B)  the principle of parsimony. 
C)  non-confounded experiments. 
D)  homogeneity of variance.

Question 17

College students who were classified as either Type A or Type B personalities came to the lab and were frustrated by the experimenter (he gave them anagrams that were unsolvable). Then the experimenter gave them a new set of (solvable) anagrams and timed how long it took them to solve them (in minutes). The following data was obtained:
 GROUP $1 =$ Type A personality
GROUP $2 =$ Type $B$ personality
Variable $=$ time to solve the anagrams
$\begin{array} { l c l l } \text { GROUP } & N & \text { Mean } & S D \ \text { GROUP 1 } & 10 & 5.34 & 1.194 \ \text { GROUP 2 } & 10 & 5.13 & 1.223 \end{array}$
$t = 1.67 \quad d f = 18 \quad p = 0.257 \quad$ Cohen's $d = .21$
-What is the independent variable?

Accepted Answer

type of pe

Question 18

College students who were classified as either Type A or Type B personalities came to the lab and were frustrated by the experimenter (he gave them anagrams that were unsolvable). Then the experimenter gave them a new set of (solvable) anagrams and timed how long it took them to solve them (in minutes). The following data was obtained:
 GROUP $1 =$ Type A personality
GROUP $2 =$ Type $B$ personality
Variable $=$ time to solve the anagrams
$\begin{array} { l c l l } \text { GROUP } & N & \text { Mean } & S D \ \text { GROUP 1 } & 10 & 5.34 & 1.194 \ \text { GROUP 2 } & 10 & 5.13 & 1.223 \end{array}$
$t = 1.67 \quad d f = 18 \quad p = 0.257 \quad$ Cohen's $d = .21$
-What is the dependent variable?

Accepted Answer

time to so

Question 19

Independent variables can

Accepted Answer

A)  contrast the presence versus the absence of some variable. 
B)  contrast "high" versus "low" amounts of some variable. 
C)  be measured rather than manipulated in an ex post facto design. 
D)  All of the above. 
A)  contrast the presence versus the absence of some variable. 
B)  contrast "high" versus "low" amounts of some variable. 
C)  be measured rather than manipulated in an ex post facto design. 
D)  All of the above.

Question 20

The general plan for selecting participants, assigning them to conditions, controlling extraneous variables, and gathering data is known as the ____________ design.

Accepted Answer

A)  control group 
B)  repeated measures 
C)  statistical 
D)  experimental 
A)  control group 
B)  repeated measures 
C)  statistical 
D)  experimental

We use _________ assignment whenever there is a relationship between the participants in the groups.

An experiment in which the experimenter directly manipulates the IV is known as a(n)

When we test participants more than once, we are using a

Certain dependent variables, such as solving puzzles and completing mazes, are difficult to administer more than once. For these research projects, researchers typically avoid which kind of design?

In a ___________ design, participants serve as their own controls.

Which of the following represents the general formula for statistical tests?

What is the difference between independent groups and correlated groups?

Was the treatment effective? How do you know? Specifically discuss the results from page 44 in your answer, explaining which findings were significant and which were not.

What does it mean when an experiment is confounded? Give an example of a confounded experiment and explain how to make the experiment unconfounded.

Distinguish between between-groups variability and error variability. Explain how these concepts factor into a general statistical formula.

The belief that explanations should remain simple until the simple explanations are no longer valid is known as the principle of

Random ___ deals with choosing your research participants, whereas random _ deals with putting those participants into groups.

The Fmax statistic is used to test the assumption of

Independent variables can

The general plan for selecting participants, assigning them to conditions, controlling extraneous variables, and gathering data is known as the ____________ design.

Psychological Research and the Research Methods Course

Developing a Good Research Idea and Conducting an Ethical Project

Qualitative Research Methods

Nonexperimental Methods: Descriptive Methods, Correlational Studies, Ex Post Facto Studies, Surveys and Questionnaires, Sampling, and Basic Research Strategies

Using the Scientific Method in Psychology

Conducting a Good Experiment I: Variables and Control

Conducting a Good Experiment Ii: Final Considerations, Unanticipated Influences, and Cross-Cultural Issues

Internal and External Validity

Using Statistics to Answer Questions

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

Designing, Conducting, Analyzing, and Interpreting Experiments With Multiple Independent Variables

Alternative Research Designs

Writing and Assembling an Apa-Format Research Report

Filters

Exam 10: Designing, Conducting, Analyzing, and Interpreting Experiments With Two Groups

We use _________ assignment whenever there is a relationship between the participants in the groups.

An experiment in which the experimenter directly manipulates the IV is known as a(n)

When we test participants more than once, we are using a

Certain dependent variables, such as solving puzzles and completing mazes, are difficult to administer more than once. For these research projects, researchers typically avoid which kind of design?

In a ___________ design, participants serve as their own controls.

Which of the following represents the general formula for statistical tests?

What is the difference between independent groups and correlated groups?

Was the treatment effective? How do you know? Specifically discuss the results from page 44 in your answer, explaining which findings were significant and which were not.

What does it mean when an experiment is confounded? Give an example of a confounded experiment and explain how to make the experiment unconfounded.

Distinguish between between-groups variability and error variability. Explain how these concepts factor into a general statistical formula.

The belief that explanations should remain simple until the simple explanations are no longer valid is known as the principle of

Random ___________ deals with choosing your research participants, whereas random _________ deals with putting those participants into groups.

The Fmax statistic is used to test the assumption of

Independent variables can

The general plan for selecting participants, assigning them to conditions, controlling extraneous variables, and gathering data is known as the ____________ design.

Psychological Research and the Research Methods Course

Developing a Good Research Idea and Conducting an Ethical Project

Qualitative Research Methods

Nonexperimental Methods: Descriptive Methods, Correlational Studies, Ex Post Facto Studies, Surveys and Questionnaires, Sampling, and Basic Research Strategies

Using the Scientific Method in Psychology

Conducting a Good Experiment I: Variables and Control

Conducting a Good Experiment Ii: Final Considerations, Unanticipated Influences, and Cross-Cultural Issues

Internal and External Validity

Using Statistics to Answer Questions

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

Designing, Conducting, Analyzing, and Interpreting Experiments With Multiple Independent Variables

Alternative Research Designs

Writing and Assembling an Apa-Format Research Report

Filters

Random ___ deals with choosing your research participants, whereas random _ deals with putting those participants into groups.