Deck 8: Experimental Designs: Between-Subjects Design

Question 1

Because random assignment is likely to create groups of different sizes,researchers often employ

A)restricted random assignment.
B)matched random assignment.
C)simple random assignment.
D)sampling.

Answer 1

A

Question 2

In a between-subjects design

A)each participant experiences only one level of the independent variable.
B)all participants experience every level of the independent variable.
C)each participant is investigated in great detail with multiple measures.
D)behavioral observation is used.

Answer 2

A

Question 3

In a between-subjects experiment,participants are assigned to treatments using random assignment.Why is random assignment used?

A)It allows the experimenter to manipulate participant variables.
B)It is an attempt to control participant variables so they don't become confounding variables.
C)It gives the experimenter an opportunity to measure participant variables that might influence the outcome of the experiment.
D)It helps to ensure that the participants in the study are representative of the general population.

Answer 3

B

Question 4

In an experiment examining the effects of running on stress levels,one group of participants is tested after running on a treadmill for 30 minutes.A week later,the same group of participants is tested after resting on a bed for 30 minutes.This is an example of a ________ design.

A)single-subjects
B)between-subjects
C)within-subjects
D)matched groups

Question 5

In a between-subjects design

A)only one score is obtained for each participant.
B)at least two scores are obtained for each participant.
C)one score is obtained for each treatment condition for each participant.
D)each score represents multiple participants.

Question 6

If a between-subjects experiment produces 50 scores in treatment 1 and 50 scores in treatment 2,then the experiment must have employed

A)50 participants.
B)100 participants.
C)25 participants.
D)200 participants.

Question 7

Which of the following is NOT a method for trying to prevent a participant characteristic (such as age or gender)from becoming a confounding variable in a between-subjects experiment?

A)Hold the participant characteristic constant.
B)Randomly assign participants to treatment conditions.
C)Randomly select the participants from the population.
D)Match the groups with respect to the participant characteristic.

Question 8

Which of the following is not a disadvantage of a between-subject design?

A)They require large numbers of participants.
B)Individual differences can produce high variance in the scores.
C)Individual differences can become confounding variables.
D)Each score is independent of all the other scores.

Question 9

In a between-subjects experiment,when the participants in one group have characteristics that are noticeably different from those in another group,the _____ of the study is threatened.

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

Question 10

A between-subjects experiment comparing four treatment conditions produces 20 scores in each treatment condition.How many scores were obtained for each participant?

A)1
B)4
C)20
D)80

Question 11

In a between-subjects experiment,when the process of assigning participants to the treatment conditions produces groups with different characteristics,the _____ of the study is threatened.

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

Question 12

An experiment that uses a different group of participants for each treatment condition is called a _____ design.

A)single-subjects
B)between-subjects
C)within-subject
D)matched groups

Question 13

When _________ occurs in a between-subjects experiment,it is impossible to determine whether differences between groups are caused by the treatments or by participant characteristics.

A)fatigue
B)practice
C)assignment bias
D)resentful demoralization

Question 14

In a between-subjects design,large individual differences can lead to

A)large variance within treatments.
B)small variance within treatments.
C)several independent variables.
D)several dependent variables.

Question 15

A between-subjects experiment comparing four treatment conditions produces 20 scores in each treatment condition.How many individuals participated in the entire experiment?

A)1
B)4
C)20
D)80

Question 16

An advantage of matching a variable across treatments rather than using random assignment to form your groups is that

A)matching reduces error due to participant differences.
B)matching is easier than randomization.
C)matching guarantees that there is no systematic relationship between participant characteristics and the treatment conditions.
D)matching ensures a nonbiased sample.

Question 17

Individual differences are

A)characteristic of the environment that differ between groups.
B)characteristics that differ from one participant to another.
C)treatment conditions that are varied between groups.
D)levels of the independent variable in a factorial design.

Question 18

A between-subjects design differs from a within-subjects design in that in a between-subjects design

A)only one group of participants is used.
B)only variables "between" the participants are examined.
C)there is a different group of participants for each of the different treatment conditions.
D)each participant is exposed to each level of the independent variable.

Question 19

Which statement best characterizes a between-subjects experimental design?

A)Participants are randomly selected from two different populations.
B)Each participant is assigned to one condition of the experiment.
C)Each participant is assigned to every condition of the experiment.
D)Participants with different characteristics make up the different conditions of the experiment.

Question 20

In a between-subjects experiment,assignment bias is a threat to

A)internal validity.
B)external validity.
C)both internal and external validity.
D)assignment bias does not threaten either internal or external validity.

Question 21

Resentful demoralization occurs when

A)an untreated group learns of the treatment received by another group and then works extra hard to show that they can perform just as well as individuals receiving the treatment.
B)an untreated group learns of the treatment received by another group and then demands the same treatment.
C)an untreated group learns of the treatment received by another group and then becomes less motivated.
D)participants withdraw from a research study before it is completed.

Question 22

When the data do not consist of numerical scores and it is impossible to examine mean differences between groups,which statistical analysis is most appropriate for a between-subjects design?

A)independent-measures t test
B)repeated-measures t test
C)single-factor analysis of variance
D)chi-square test for independence

Question 23

The single-factor two-group design includes

A)only two levels of one independent variable.
B)a treatment and a control group.
C)two dependent variables.
D)multiple treatment and control groups.

Question 24

When comparing means in a two-group design,which statistical analysis is most appropriate?

A)independent-measures t test
B)repeated-measures t test
C)single-factor analysis of variance
D)chi-square test for independence

Question 25

When comparing means in a single-factor multiple group design which statistical analysis is most appropriate?

A)independent-measures t test
B)repeated-measures t test
C)single-factor analysis of variance
D)chi-square test for independence

Question 26

A disadvantage of the two-group design is that it

A)provides limited information about the effect of the independent variable
B)is complicated.
C)maximizes the differences between the groups.
D)requires the use of regression analyses to analyze the data.

Question 27

Holding a participant characteristic (such as age or gender)constant strengthens _____ and weakens _____.

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

Question 28

What is the most common statistical analysis for a single-factor two-group design?

A)ANOVA
B)independent-measures t test repeated-measures t test
C)regression

Question 29

In a between-subjects design,you can increase the likelihood of finding a difference between the treatment conditions by

A)including several independent variables in your experiment.
B)including several dependent variables in your experiment.
C)taking steps to minimize variance within groups.
D)taking steps to maximize variance within groups.

Question 30

What is the most common statistical analysis for a single-factor multiple-group design?

A)ANOVA
B)Independent-measures t test
C)Repeated-measures t test
D)Regression

Question 31

An advantage of holding a variable constant rather than using random assignment to form your groups is that

A)holding a variable constant reduces error due to participant differences.
B)holding a variable constant is easier than randomization.
C)holding a variable constant guarantees that there is no systematic relationship between participant characteristics and the treatment conditions.
D)holding a variable constant ensures a nonbiased sample.

Question 32

Researchers typically try to

A)increase the differences between treatments and decrease the variance within treatments.
B)decrease the differences between treatments and increase the variance within treatments.
C)increase the differences between treatments and increase the variance within treatments.
D)decrease the differences between treatments and decrease the variance within treatments.

Question 33

Diffusion refers to

A)differences in one group of participants from another group.
B)the resentment of the untreated group.
C)the spreading of treatment effects from the experimental to the control group.
D)the demands of the untreated group to receive equal treatment.

Question 34

Which of the following is not a risk when participants in one group have an opportunity to talk with participants in the other groups in a between-subjects experiment?

A)resentful demoralization
B)compensatory equalization
C)diffusion
D)differential attrition

Question 35

A limitation of using matching rather than random assignment to form groups in a between-subjects experiment is that

A)matching requires another measurement procedure.
B)matching reduces error due to participant differences.
C)matching is easier than randomization.
D)matching eliminates any systematic relationship between participant characteristics and the treatment conditions.

Question 36

Standardizing procedures across treatment conditions

A)minimizes variance within treatments.
B)maximizes variance within treatments.
C)guarantees that there is no systematic relationship between participant characteristics and the treatment conditions.
D)maximizes differences between groups.

Question 37

The primary limitation of a two-group design is that

A)it is simple to interpret.
B)it increases the chances of demonstrating a significant mean difference.
C)it tends to reduce the differences between the groups.
D)it may not provide a complete picture of the relationship between the variables.

Question 38

Holding a variable constant prevents a variable from becoming a confound by

A)eliminating the possibility that the variable will be substantially different from one group to another.
B)reducing error.
C)ensuring a nonbiased sample.
D)increasing the differences between the groups.

Question 39

A limitation of a single-factor multiple group design is that

A)the mean differences between the groups become smaller as more groups are used.
B)it is simple to interpret.
C)it increases the chances of demonstrating a significant mean difference.
D)it may not provide a complete picture of the relationship between the variables.

Question 40

Which of the following does not guarantee that a specific participant variable does not become a confounding variable?

A)matching the variable across treatments
B)randomizing the variable across treatment
C)holding the variable constant
D)all of the other options guarantee that the variable does not become a confounding variable

Question 41

A between-subjects experiment with 25 scores in treatment I and 25 scores in treatment II must have a total of 25 participants in the experiment.

Question 42

Matching a variable across treatment guarantees that the variable cannot become a confounding variable.

Question 43

In a between-subjects experiment,increasing the variance within treatments increases the likelihood of finding significant differences between treatments.

Question 44

For a between-subjects experiment,any factor that increases the variance within treatments also increases the likelihood of finding a significant difference between treatments.

Question 45

Assignment bias can threaten the internal validity of between-subjects experiments.

Question 46

Random assignment guarantees that participant characteristics do not become a confounding variable.

Question 47

Between-subjects designs are often called repeated-measures designs.

Question 48

Resentful demoralization is a threat to the external validity of a between-subjects experiment.

Question 49

In a between-subjects experimental design individual differences can become a confounding variable.

Question 50

One characteristic of a between-subjects design is that the data consist of exactly one score for each participant.

Question 51

Differential attrition can threaten the internal validity of a between-subjects experiment.

Question 52

A disadvantage of holding a variable constant is that it limits an experiment's external validity.

Question 53

In a between-subjects experiment,if the participants in one group are noticeably older than the participants in another group,then participant age is a confounding variable and threatens the internal validity of the experiment.

Question 54

Holding a variable constant guarantees that the variable cannot become a confounding variable.

Question 55

One advantage of a between-subjects design is that each score is completely independent of the other scores in the data.

Question 56

A between-subjects experiment comparing three treatments requires three separate groups of participants.

Question 57

Randomizing a variable across treatments guarantees that the variable cannot become a confounding variable.

Question 58

In a between-subjects experiment,one way to reduce the variance within treatments is to create more homogeneous groups by holding constant a participant characteristic such as age or gender.

Question 59

An advantage of between-subjects designs is that they require fewer participants than are typically needed for within-subjects designs.

Question 60

Holding a participant variable constant has the double advantage of (1)preventing the variable from becoming a confounding variable,and (2)reducing variance within groups.

Question 61

Describe the advantages and disadvantages of matching groups of participants in a between-subjects experiment.

Question 62

Explain the benefit of independent scores in a between-subjects design.

Question 63

Describe why the assignment of subjects to the conditions of an experiment in a between-subjects design is such a critical issue.

Question 64

Describe the advantages and disadvantages of holding a participant characteristic constant in a between-subjects experiment.

Question 65

Describe some of the problems that can develop if participants from different treatment conditions have an opportunity to talk with each other during the course of the experiment.

Question 66

Create an example of a between-subjects experiment.Identify the independent and dependent variables and briefly describe the experiment.Indicate the number of levels of the independent variable and identify them.

Question 67

Describe the basic characteristics of a between-subjects experiment.