Question 1

Describe the directionality problem and explain how researchers attempt to avoid this problem in an experiment.

Accepted Answer

It is possible to demonstrate a relationship between two variables by simply observing them. However, simple observation cannot establish the direction of the relationship. For example, you may observe that two variables change together consistently: as variable A increases, variable B also increases. However, you cannot determine whether changes in A are causing changes in B, or whether changes in B are causing changes in A. To avoid this problem in an experiment, the researcher takes charge and manipulates one of the variables. For example, the researcher increases the value of variable A and then observes variable B to see if it is affected by the increase. If B also increases, then the researcher can conclude that changing variable A has caused changes in variable B.

Question 2

Explain why manipulation of an independent variable is a necessary component of an experiment.

Accepted Answer

In an experiment, manipulation of the independent variable is necessary to avoid the directionality problem and to establish the direction of the relationship. The intent is to demonstrate that the manipulation of one variable (the independent variable) causes changes to occur in a second variable (the dependent variable).

Question 3

In an experiment, participants are randomly assigned to treatment conditions ____.

Accepted Answer

A)  to help protect the internal validity of the study 
B)  to help protect the external validity of the study 
C)  to help protect both the internal and external validity 
D)  as an alternative to manipulation of variables 
A)  to help protect the internal validity of the study 
B)  to help protect the external validity of the study 
C)  to help protect both the internal and external validity 
D)  as an alternative to manipulation of variables A

Question 4

Explain the primary advantage and disadvantage of simulation and field studies.

Accepted Answer

The main advantage of simulation and fie

Question 5

Dr. Jones systematically varies the brightness in the laboratory (400, 800, and 1600 lumens) while holding other variables constant, and observes that the participants' activity level decreases as the brightness decreases. This illustrates ____.

Accepted Answer

A)  a noncausal relationship between brightness and activity level 
B)  a causal relationship between brightness and activity level 
C)  no relationship between brightness and activity level 
D)  a nonsystematic relationship between brightness and activity level 
A)  a noncausal relationship between brightness and activity level 
B)  a causal relationship between brightness and activity level 
C)  no relationship between brightness and activity level 
D)  a nonsystematic relationship between brightness and activity level

Question 6

In New York State, the winter months produce higher heating bills and higher levels of depression. Although the numbers show that higher heating bills are related to higher levels of depression, what most likely explains this relationship?

Accepted Answer

A)  Cause and effect 
B)  The directionality problem 
C)  The third-variable problem 
D)  The extraneous variable problem 
A)  Cause and effect 
B)  The directionality problem 
C)  The third-variable problem 
D)  The extraneous variable problem

Question 7

Dr. Ramos is interested in studying how indoor temperature can influence people's sleep quality during the summer. A sample of 100 households is selected in which the residents keep their houses at 76 degrees during the summer. The residents wear a monitoring device that measures their sleep cycles for several nights to get baseline readings. Then, 50 of the homes are randomly assigned to the warm temperature condition in which the residents agree to keep their houses at 82 degrees Fahrenheit. In the other 50 houses, the residents agree to keep their houses at 70 degrees. For several nights, Dr. Ramos collects the sleep data for the people living in the houses to see how the residents' sleep patterns have changed. In this example, the sleep quality of participants is the ____ variable.

Accepted Answer

A)  dependent 
B)  extraneous 
C)  correlational 
D)  independent 
A)  dependent 
B)  extraneous 
C)  correlational 
D)  independent

Question 8

An experiment includes a treatment condition, a no-treatment control, and a placebo control. Which two conditions should be compared to determine the size of the effect that is actually caused by the treatment?

Accepted Answer

A)  Placebo versus treatment 
B)  Placebo versus no-treatment 
C)  Treatment versus no-treatment 
D)  Placebo control only 
A)  Placebo versus treatment 
B)  Placebo versus no-treatment 
C)  Treatment versus no-treatment 
D)  Placebo control only

Question 9

The manipulated variable in an experiment is the ____ variable.

Accepted Answer

A)  independent 
B)  dependent 
C)  extraneous 
D)  confounding 
A)  independent 
B)  dependent 
C)  extraneous 
D)  confounding

Question 10

A researcher exposes people to a stressful situation (such as public speaking) to examine the effect of stress on depressed mood. The researcher includes a measure of stress as a ____.

Accepted Answer

A)  measure of the dependent variable 
B)  measure of extraneous variables 
C)  control for confounding variables 
D)  manipulation check 
A)  measure of the dependent variable 
B)  measure of extraneous variables 
C)  control for confounding variables 
D)  manipulation check

Question 11

What is the advantage of a simulation compared to a traditional laboratory study?

Accepted Answer

A)  Increased internal validity 
B)  Increased external validity 
C)  Increased reliability 
D)  Elimination of history effects 
A)  Increased internal validity 
B)  Increased external validity 
C)  Increased reliability 
D)  Elimination of history effects

Question 12

Although field studies tend to have higher external validity that traditional laboratory studies, they also tend to have ____.

Accepted Answer

A)  lower internal validity 
B)  lower reliability 
C)  an increased risk of confounding from history effects 
D)  an increased risk of finding no effect of the manipulation 
A)  lower internal validity 
B)  lower reliability 
C)  an increased risk of confounding from history effects 
D)  an increased risk of finding no effect of the manipulation

Question 13

Holding a variable constant is a technique for removing one threat to ____ but it can limit the ____ of an experiment.

Accepted Answer

A)  internal validity; external validity 
B)  external validity; internal validity 
C)  internal validity; reliability 
D)  external validity; reliability 
A)  internal validity; external validity 
B)  external validity; internal validity 
C)  internal validity; reliability 
D)  external validity; reliability

Question 14

Explain why control of extraneous variables is a necessary component of an experiment.

Accepted Answer

In an experiment, control of extraneous

Question 15

Research indicates the people who suffer from depression also tend to experience insomnia. However, it is unclear whether the depression causes insomnia or the lack of sleep causes depression. This is an example of the ____.

Accepted Answer

A)  directionality problem 
B)  third-variable problem 
C)  extraneous variable problem 
D)  manipulation check problem 
A)  directionality problem 
B)  third-variable problem 
C)  extraneous variable problem 
D)  manipulation check problem

Question 16

What is the purpose for using a control condition in an experiment?

Accepted Answer

A)  It provides a baseline to evaluate the size of the treatment effect. 
B)  It minimizes the threat of a confounding variable. 
C)  It is necessary to ensure the internal validity of the study. 
D)  It is necessary to ensure the external validity of the study. 
A)  It provides a baseline to evaluate the size of the treatment effect. 
B)  It minimizes the threat of a confounding variable. 
C)  It is necessary to ensure the internal validity of the study. 
D)  It is necessary to ensure the external validity of the study.

Question 17

To demonstrate a cause-and-effect relationship between two variables, a researcher must make one of the variables change rather than waiting for it to change naturally.

Accepted Answer

A) True 
 B)False

Question 18

A researcher reports that participants made fewer errors on a simulated air-traffic-control task when quiet background music was playing than when there was no music. For this study, the number of errors is the independent variable.

Accepted Answer

A) True 
 B)False

Question 19

Why is a confounding variable unacceptable in a true experiment?

Accepted Answer

A)  It can distort the effect of the independent variable. 
B)  It can disrupt the normal behavior of participants. 
C)  It threatens internal validity by providing an alternative explanation for the results. 
D)  It creates a directionality problem that undermines a cause-and-effect conclusion. 
A)  It can distort the effect of the independent variable. 
B)  It can disrupt the normal behavior of participants. 
C)  It threatens internal validity by providing an alternative explanation for the results. 
D)  It creates a directionality problem that undermines a cause-and-effect conclusion.

Question 20

Dr. Nguyen is studying how amount of sleep influences mood for kindergarteners. A sample of 100 children is selected. Fifty children are allowed to sleep for 11 hours each night. The other 50 children are awoken after 8 hours. After three nights, Dr. Nguyen records the mood for each child and compares the two groups of scores. In this example, how many levels are there for the independent variable?

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  100 
A)  1 
B)  2 
C)  3 
D)  100

Describe the directionality problem and explain how researchers attempt to avoid this problem in an experiment.

Explain why manipulation of an independent variable is a necessary component of an experiment.

In an experiment, participants are randomly assigned to treatment conditions ____.

Explain the primary advantage and disadvantage of simulation and field studies.

Dr. Jones systematically varies the brightness in the laboratory (400, 800, and 1600 lumens) while holding other variables constant, and observes that the participants' activity level decreases as the brightness decreases. This illustrates ____.

In New York State, the winter months produce higher heating bills and higher levels of depression. Although the numbers show that higher heating bills are related to higher levels of depression, what most likely explains this relationship?

An experiment includes a treatment condition, a no-treatment control, and a placebo control. Which two conditions should be compared to determine the size of the effect that is actually caused by the treatment?

The manipulated variable in an experiment is the ____ variable.

A researcher exposes people to a stressful situation (such as public speaking) to examine the effect of stress on depressed mood. The researcher includes a measure of stress as a ____.

What is the advantage of a simulation compared to a traditional laboratory study?

Although field studies tend to have higher external validity that traditional laboratory studies, they also tend to have ____.

Holding a variable constant is a technique for removing one threat to but it can limit the of an experiment.

Explain why control of extraneous variables is a necessary component of an experiment.

Research indicates the people who suffer from depression also tend to experience insomnia. However, it is unclear whether the depression causes insomnia or the lack of sleep causes depression. This is an example of the ____.

What is the purpose for using a control condition in an experiment?

To demonstrate a cause-and-effect relationship between two variables, a researcher must make one of the variables change rather than waiting for it to change naturally.

A researcher reports that participants made fewer errors on a simulated air-traffic-control task when quiet background music was playing than when there was no music. For this study, the number of errors is the independent variable.

Why is a confounding variable unacceptable in a true experiment?

Introduction, Acquiring Knowledge, and the Scientific Method

Research Ideas and Hypotheses

Defining and Measuring Variables

Ethics in Research

Selecting Research Participants

Research Strategies and Validity

Experimental Designs: Between-Subjects Design

Experimental Designs: Within-Subjects Design

The Nonexperimental and Quasi-Experimental Strategies: Nonequivalent Group, Prepost, and Developmental Designs

Factorial Designs

The Correlational Research Strategy

The Descriptive Research Strategy

Single-Case Experimental Research Designs

Statistical Evaluation of Data

Writing an Apa-Style Research Report

Filters

Exam 7: The Experimental Research Strategy

Describe the directionality problem and explain how researchers attempt to avoid this problem in an experiment.

Explain why manipulation of an independent variable is a necessary component of an experiment.

In an experiment, participants are randomly assigned to treatment conditions ____.

Explain the primary advantage and disadvantage of simulation and field studies.

Dr. Jones systematically varies the brightness in the laboratory (400, 800, and 1600 lumens) while holding other variables constant, and observes that the participants' activity level decreases as the brightness decreases. This illustrates ____.

In New York State, the winter months produce higher heating bills and higher levels of depression. Although the numbers show that higher heating bills are related to higher levels of depression, what most likely explains this relationship?

An experiment includes a treatment condition, a no-treatment control, and a placebo control. Which two conditions should be compared to determine the size of the effect that is actually caused by the treatment?

The manipulated variable in an experiment is the ____ variable.

A researcher exposes people to a stressful situation (such as public speaking) to examine the effect of stress on depressed mood. The researcher includes a measure of stress as a ____.

What is the advantage of a simulation compared to a traditional laboratory study?

Although field studies tend to have higher external validity that traditional laboratory studies, they also tend to have ____.

Holding a variable constant is a technique for removing one threat to ____ but it can limit the ____ of an experiment.

Explain why control of extraneous variables is a necessary component of an experiment.

Research indicates the people who suffer from depression also tend to experience insomnia. However, it is unclear whether the depression causes insomnia or the lack of sleep causes depression. This is an example of the ____.

What is the purpose for using a control condition in an experiment?

To demonstrate a cause-and-effect relationship between two variables, a researcher must make one of the variables change rather than waiting for it to change naturally.

A researcher reports that participants made fewer errors on a simulated air-traffic-control task when quiet background music was playing than when there was no music. For this study, the number of errors is the independent variable.

Why is a confounding variable unacceptable in a true experiment?

Introduction, Acquiring Knowledge, and the Scientific Method

Research Ideas and Hypotheses

Defining and Measuring Variables

Ethics in Research

Selecting Research Participants

Research Strategies and Validity

Experimental Designs: Between-Subjects Design

Experimental Designs: Within-Subjects Design

The Nonexperimental and Quasi-Experimental Strategies: Nonequivalent Group, Prepost, and Developmental Designs

Factorial Designs

The Correlational Research Strategy

The Descriptive Research Strategy

Single-Case Experimental Research Designs

Statistical Evaluation of Data

Writing an Apa-Style Research Report

Filters

Holding a variable constant is a technique for removing one threat to but it can limit the of an experiment.