,PSYC 255 Quiz 3 | Introduction to Research (2026)
Q&A | Liberty University
1. What is the primary purpose of a between-subjects design in psychological
research?
A) To measure the same participants across multiple conditions
B) To assign different participants to each condition of the experiment
C) To eliminate the need for a control group
D) To observe participants without manipulating any variables
Correct Answer: To assign different participants to each condition of the
experiment
Rationale: A between-subjects design involves assigning different participants to
each condition, meaning each person experiences only one level of the independent
variable. This approach minimizes carryover effects but requires more participants.
Within-subjects designs, by contrast, expose the same participants to all conditions.
2. What is a key advantage of using a within-subjects design?
A) It requires fewer participants than a between-subjects design
B) It eliminates the possibility of order effects
C) It makes counterbalancing unnecessary
D) It allows researchers to ignore individual differences
Correct Answer: It requires fewer participants than a between-subjects design
,Rationale: Because each participant serves in every condition, within-subjects
designs require fewer participants overall. However, they are vulnerable to order
effects, which must be controlled through counterbalancing. Individual differences
are controlled but not ignored.
3. In a within-subjects experiment, what is a carryover effect?
A) The influence of one condition on performance in a subsequent condition
B) The effect of the independent variable on the dependent variable
C) The influence of the researcher on the participant's behavior
D) The effect of the control group on the experimental group
Correct Answer: The influence of one condition on performance in a subsequent
condition
Rationale: A carryover effect occurs when exposure to one condition affects how
participants respond in a later condition. Counterbalancing is used to distribute these
effects evenly across conditions. It is distinct from main effects and experimenter
bias.
4. What is the purpose of counterbalancing in a within-subjects design?
A) To increase the sample size
B) To control for order effects
C) To randomly assign participants to groups
D) To eliminate the need for a control group
, Correct Answer: To control for order effects
Rationale: Counterbalancing involves presenting conditions in different orders to
different participants, which helps distribute any order or carryover effects evenly. It
does not increase sample size or replace control groups.
5. What does a null hypothesis state?
A) There is a relationship between the variables
B) There is no difference or relationship between the variables
C) The research hypothesis is correct
D) The results are statistically significant
Correct Answer: There is no difference or relationship between the variables
Rationale: The null hypothesis is the default assumption that any observed
difference is due to chance. Researchers aim to reject it in favor of the research
hypothesis. It does not state that a relationship exists.
6. In hypothesis testing, what does it mean for two hypotheses to be mutually
exclusive?
A) Both hypotheses can be true at the same time
B) Only one of the hypotheses can be true
C) Neither hypothesis can be tested
D) Both hypotheses must be rejected
Q&A | Liberty University
1. What is the primary purpose of a between-subjects design in psychological
research?
A) To measure the same participants across multiple conditions
B) To assign different participants to each condition of the experiment
C) To eliminate the need for a control group
D) To observe participants without manipulating any variables
Correct Answer: To assign different participants to each condition of the
experiment
Rationale: A between-subjects design involves assigning different participants to
each condition, meaning each person experiences only one level of the independent
variable. This approach minimizes carryover effects but requires more participants.
Within-subjects designs, by contrast, expose the same participants to all conditions.
2. What is a key advantage of using a within-subjects design?
A) It requires fewer participants than a between-subjects design
B) It eliminates the possibility of order effects
C) It makes counterbalancing unnecessary
D) It allows researchers to ignore individual differences
Correct Answer: It requires fewer participants than a between-subjects design
,Rationale: Because each participant serves in every condition, within-subjects
designs require fewer participants overall. However, they are vulnerable to order
effects, which must be controlled through counterbalancing. Individual differences
are controlled but not ignored.
3. In a within-subjects experiment, what is a carryover effect?
A) The influence of one condition on performance in a subsequent condition
B) The effect of the independent variable on the dependent variable
C) The influence of the researcher on the participant's behavior
D) The effect of the control group on the experimental group
Correct Answer: The influence of one condition on performance in a subsequent
condition
Rationale: A carryover effect occurs when exposure to one condition affects how
participants respond in a later condition. Counterbalancing is used to distribute these
effects evenly across conditions. It is distinct from main effects and experimenter
bias.
4. What is the purpose of counterbalancing in a within-subjects design?
A) To increase the sample size
B) To control for order effects
C) To randomly assign participants to groups
D) To eliminate the need for a control group
, Correct Answer: To control for order effects
Rationale: Counterbalancing involves presenting conditions in different orders to
different participants, which helps distribute any order or carryover effects evenly. It
does not increase sample size or replace control groups.
5. What does a null hypothesis state?
A) There is a relationship between the variables
B) There is no difference or relationship between the variables
C) The research hypothesis is correct
D) The results are statistically significant
Correct Answer: There is no difference or relationship between the variables
Rationale: The null hypothesis is the default assumption that any observed
difference is due to chance. Researchers aim to reject it in favor of the research
hypothesis. It does not state that a relationship exists.
6. In hypothesis testing, what does it mean for two hypotheses to be mutually
exclusive?
A) Both hypotheses can be true at the same time
B) Only one of the hypotheses can be true
C) Neither hypothesis can be tested
D) Both hypotheses must be rejected
