Deck 8: Experimental Designs: Between-Subjects Design

Question 1

A design that compares different groups of scores obtained from separate groups of participants is a ____ design.

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

Answer 1

B

Question 2

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

Answer 2

B

Question 3

If there are many individual differences that could confound your study, what is the best approach for creating equivalent groups in that case?

A) Holding the variables constant
B) Using random assignment
C) Matching groups of participants
D) Restricting the range of values for all extraneous variables

Answer 3

B

Question 4

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 5

In an experiment examining the effects of background noise on people's ability to understand a verbal message, one group of participants is given a comprehension quiz after listening to a passage being read to them with no background noise. For comparison, a second group of participants is given a comprehension quiz after listening to a passage being read to them with 60 decibels of conversation as background noise. This is an example of a ____ design.

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

Question 6

An advantage of a between-subject design is that ____.

A) scores are influenced by practice effects
B) scores are influenced by fatigue
C) each score is independent of all the other scores
D) they require large numbers of participants

Question 7

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 8

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

Question 9

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 10

If a between-subjects study explores the effect of caffeine on appetite by comparing the appetites of teenagers with no caffeine in their systems with middle-aged adults with 100 mg of caffeine in their system, the study is ________.

A) fatigued
B) confounded
C) demoralized
D) statistically significant

Question 11

In a between-subjects design, the separate groups must be as ____.

A) similar in participant characteristics as possible
B) different in all environmental variables as possible
C) similar in treatment conditions as possible
D) similar on the dependent variable measures as possible

Question 12

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 treatment conditions
D) each participant is exposed to each level of the independent variable

Question 13

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 are assigned to a random number of conditions.

Question 14

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

A) requires another level of work
B) increases error due to participant differences
C) requires at least twice as many participants
D) increases the need for control groups

Question 15

Why is random assignment used in between-subjects experimental designs?

A) To hold participant characteristics constant
B) To ensure a nonbiased sample
C) To ensure anonymity of the research participants
D) To eliminate systematic differences between the groups

Question 16

Compared to within-subjects designs, between-subjects designs require relatively ____.

A) larger numbers of participants
B) smaller numbers of participants
C) less control of individual difference
D) more concern for practice effects

Question 17

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 18

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

A) reduces error due to participant differences
B) is easier than randomization
C) prevents confounding
D) ensures a nonbiased sample

Question 19

In an experiment examining the effects of background noise on people's ability to understand a verbal message, one group of participants is given a comprehension quiz after listening to a passage being read to them with no background noise. A week later, the same group of participants is given a comprehension quiz after listening to a passage being read to them with 60 decibels of conversation as background noise. This is an example of a ____ design.

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

Question 20

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

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

Question 21

Diffusion is a threat to the _____ of a study.

A) variance
B) external validity
C) internal validity
D) statistical significance

Question 22

Standardizing procedures, standardizing treatment settings, and limiting individual differences all have the effect of ____.

A) reducing variance between treatments
B) increasing variance within treatments
C) increasing variance between treatments
D) reducing variance within treatments

Question 23

Which risk to a study exists whether or not participants in different groups are able to communicate with each other?

A) Resentful demoralization
B) Compensatory equalization
C) Diffusion
D) Differential attrition

Question 24

Compensatory equalization 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 25

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

A) mean differences between the groups become smaller as more groups are used
B) interpretation is too simplistic
C) chances of demonstrating a significant mean difference are increased
D) complete picture of the relationship between the variables cannot be seen

Question 26

Limiting individual differences is a way to ____.

A) standardize procedures
B) standardize treatment settings
C) reduce the variance within treatments
D) maximize the variance within treatments

Question 27

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 28

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 29

The primary limitation of a two-group design is that it ____.

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

Question 30

Differential attrition refers to ____.

A) differences in one group of participants from another group
B) differences in the number of withdrawals among experimental groups
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 31

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 32

In a between-subjects design, large individual differences can produce ____.

A) large between-treatment differences, making it easier to see real treatment effects
B) small within-treatment variance, making it easier to see real treatment effects
C) large within-treatment variance, making it difficult to see real treatment effects
D) small between-treatment difference, making it difficult to see real treatment effects

Question 33

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

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

Question 34

In a between-subjects design, individual differences (participant variables) are a problem because they can ____.

A) cause diffusion and attrition
B) increase variability of the scores
C) preclude the use of statistical analyses
D) produce fatigue effects

Question 35

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 36

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 37

Resentful demoralization occurs when _____.

A) an untreated group learns of the treatment received by another group and then becomes less motivated
B) participants in an untreated group leave the study because they become bored with the treatment procedure or don't see it as effective
C) participants in an untreated group are not allowed to communicate with participants in a treated group despite knowing each other well before the study
D) 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

Question 38

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 39

Holding a variable constant prevents a participant characteristic from confounding a study by ____.

A) eliminating variability in that characteristic
B) reducing error
C) ensuring a nonbiased sample
D) increasing the differences between the groups

Question 40

Increasing variance within groups ____ the likelihood of finding a difference between the treatment conditions.

A) increases
B) decreases
C) does not affect
D) increases, then decreases

Question 41

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

Question 42

Validity is threatened in a between-subjects design when participants in one group have an opportunity to talk with participants in the other.

Question 43

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

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

One advantage of holding a variable constant is that it can reduce variance within a group.

Question 46

Using a small sample size can help minimize the problems with variance.

Question 47

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 48

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 49

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

Question 50

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 51

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

Question 52

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

Question 53

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

Question 54

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

Question 55

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

Question 56

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

Question 57

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

Question 58

In a between-subjects design, to compare proportions between groups, an independent-measures t -test is appropriate.

Question 59

Researchers use random assignment in an effort to create groups that are as similar as possible.

Question 60

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

Question 61

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 62

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

Question 63

Explain the advantages and disadvantages of multiple-group designs.

Question 64

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 65

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

Question 66

Describe the basic characteristics of a between-subjects experiment.

Question 67

Explain what differential attrition is and how it negatively affects an experiment.