,PSYC 255 Quiz 5 | Introduction to Research (2026)
Q&A | Liberty University
1. What is the primary purpose of a within-subjects design in psychological research?
A) To assign different participants to each condition
B) To expose the same participants to all levels of the independent variable
C) To eliminate the need for a control group
D) To observe participants without manipulating any variables
Correct Answer: To expose the same participants to all levels of the independent
variable
Rationale: A within-subjects design exposes the same participants to all levels or
conditions of the independent variable. This approach controls for individual
differences but is susceptible to order effects such as practice, fatigue, and carryover
effects.
2. A researcher is conducting a within-subjects design. Participants are failing to fully
complete the last level of the independent variable, leaving questions blank and
showing less effort than in the first level. What disadvantage of within-subjects
design is being observed?
A) Practice effects
B) Fatigue
C) Selection bias
D) Attrition
,Correct Answer: Fatigue
Rationale: Fatigue occurs in within-subjects designs when participants become
tired or less motivated as they progress through multiple conditions, leading to
decreased performance in later conditions. Practice effects involve improvement
from repeated exposure, while selection bias and attrition are separate concerns.
3. What are order effects in a within-subjects design?
A) The influence of the sequence in which conditions are presented on participant
performance
B) The effect of the independent variable on the dependent variable
C) The influence of the researcher on participant behavior
D) The effect of the control group on the experimental group
Correct Answer: The influence of the sequence in which conditions are presented
on participant performance
Rationale: Order effects occur when the order in which conditions are presented
affects participant performance, independent of the manipulation itself.
Counterbalancing is used to control for order effects. It is distinct from main effects
and experimenter bias.
4. According to the textbook, what is statistical variance?
A) The degree of spread among data surrounding the mean
B) The middle score in a distribution
C) The most frequently occurring score
, D) The difference between the highest and lowest scores
Correct Answer: The degree of spread among data surrounding the mean
Rationale: Statistical variance measures the degree of spread among data points
surrounding the mean. It is calculated by averaging the squared deviations from the
mean. Standard deviation is the square root of variance, and range is the difference
between the highest and lowest scores.
5. Which of the following statements about hypotheses is true?
A) The two hypotheses developed must be mutually exclusive and exhaustive
B) Hypotheses should be broad and general
C) Only one hypothesis is needed for a study
D) Hypotheses cannot be tested empirically
Correct Answer: The two hypotheses developed must be mutually exclusive and
exhaustive
Rationale: In research, the null and research hypotheses must be mutually
exclusive (only one can be true) and exhaustive (they cover all possible outcomes).
This ensures that the hypothesis testing process is logically sound.
6. What does it mean when hypotheses are said 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
Q&A | Liberty University
1. What is the primary purpose of a within-subjects design in psychological research?
A) To assign different participants to each condition
B) To expose the same participants to all levels of the independent variable
C) To eliminate the need for a control group
D) To observe participants without manipulating any variables
Correct Answer: To expose the same participants to all levels of the independent
variable
Rationale: A within-subjects design exposes the same participants to all levels or
conditions of the independent variable. This approach controls for individual
differences but is susceptible to order effects such as practice, fatigue, and carryover
effects.
2. A researcher is conducting a within-subjects design. Participants are failing to fully
complete the last level of the independent variable, leaving questions blank and
showing less effort than in the first level. What disadvantage of within-subjects
design is being observed?
A) Practice effects
B) Fatigue
C) Selection bias
D) Attrition
,Correct Answer: Fatigue
Rationale: Fatigue occurs in within-subjects designs when participants become
tired or less motivated as they progress through multiple conditions, leading to
decreased performance in later conditions. Practice effects involve improvement
from repeated exposure, while selection bias and attrition are separate concerns.
3. What are order effects in a within-subjects design?
A) The influence of the sequence in which conditions are presented on participant
performance
B) The effect of the independent variable on the dependent variable
C) The influence of the researcher on participant behavior
D) The effect of the control group on the experimental group
Correct Answer: The influence of the sequence in which conditions are presented
on participant performance
Rationale: Order effects occur when the order in which conditions are presented
affects participant performance, independent of the manipulation itself.
Counterbalancing is used to control for order effects. It is distinct from main effects
and experimenter bias.
4. According to the textbook, what is statistical variance?
A) The degree of spread among data surrounding the mean
B) The middle score in a distribution
C) The most frequently occurring score
, D) The difference between the highest and lowest scores
Correct Answer: The degree of spread among data surrounding the mean
Rationale: Statistical variance measures the degree of spread among data points
surrounding the mean. It is calculated by averaging the squared deviations from the
mean. Standard deviation is the square root of variance, and range is the difference
between the highest and lowest scores.
5. Which of the following statements about hypotheses is true?
A) The two hypotheses developed must be mutually exclusive and exhaustive
B) Hypotheses should be broad and general
C) Only one hypothesis is needed for a study
D) Hypotheses cannot be tested empirically
Correct Answer: The two hypotheses developed must be mutually exclusive and
exhaustive
Rationale: In research, the null and research hypotheses must be mutually
exclusive (only one can be true) and exhaustive (they cover all possible outcomes).
This ensures that the hypothesis testing process is logically sound.
6. What does it mean when hypotheses are said 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
