PSY 3213 Final Exam
The possibility that a third variable is the reason for the relationship between x and y is a problem for
the relationship between x and y is a problem with what type of validity? Correct Answer: Internal
Validity
Intelligence is related to SAT score, but the relationship is actually due to SES.
What is a bivariate correlation and what type of claim is usually made from them? Correct Answer: A
bivariate correlation is an association between two variables. Associational claims are made from
bivariate correlations.
What is the relationship between moderators and external validity? Correct Answer: When
generalizability is affected by moderators, your association may not generalize to all groups of people
Lisa finds a strong positive correlation between impulsivity and rash decision-making.
r = 0.8, p < 0.05.
It turns out there were several pathological gamblers in her sample. Pathological gamblers score
unusually high on impulsivity measures. When she takes these people out, what will happen to the
correlation? Increase or decrease? Correct Answer: Decrease. Removing the outliers will weaken the
correlation.
What are the three rules for causal claims? Correct Answer: Temporal precedence - IV comes before
DV.
Covariance - As A changes B changes.
Internal validity - there is no third variable that describes the relationship (cannot tell from associational)
What type of research design involves measuring the same variables, from the same people, across
different time points? There is no manipulation involved. Correct Answer: Longitudinal
When a relationship between two variables depends on the level of a third variable, that kind of third
variable is called a _________? Correct Answer: Moderator
(Effect is stronger in one subgroup v. another)
Autocorrelation: The association of the variable with itself across time Correct Answer: This diagram
illustrates what kind of correlation?
Cross-Lag Correlation: The association of an earlier measure of one variable with the later measure of
another variable Correct Answer: This diagram illustrates what kind of correlation?
As sleep increases, exam scores increase, even after controlling for time studying and age Correct
Answer: Dr. Bazinga conducts a study examining whether there is a link between exam scores and
sleep. But, he wants to see if any other variables (time studying, age) can explain the relationship. How
might you interpret the result of sleep?
This method assigns people to groups in experiments. It ensures that features of people are 'equated'
except on the independent variable. Correct Answer: Random assignment
, __________ is a simple study that uses a separate group of participants that is generally completed
before conducting the study of primary interest in order to confirm the effectiveness of a manipulation
Correct Answer: A pilot study
Eric designs a study to examine drink preferences of university freshmen. In the study, all participants
drink a cup of coffee then rate their enjoyment of the coffee, then drink a cup of tea and rate their
enjoyment of the tea, and finally drink a cup of milk and rate their enjoyment of the milk. Eric tells
Theresa about the plans for his study and she says she is concerned that he could have a problem of ___
effect in his study. How can Eric fix this problem? Correct Answer: Order effect
Counterbalancing (presenting levels of the IV to participants in different orders)
In a business class experiment on the endowment effect, Theo is comparing the value of a coffee mug to
someone who owns it and is selling it to someone who is buying it. The endowment effect is the
tendency of sellers to value something they own more than buyers do. Participants are randomly
assigned to be buyers or sellers of a mug with their first name on it. Buyers select the maximum price
they would pay for the mug. Sellers select the minimum price they would accept for the mug. Theo then
compares the buyers' and sellers' prices. What kind of design is this? Correct Answer: Posttest only
Expert dancers in foxtrot and tango were recruited from dance studios and participated in Nick's study.
Their task was to listen to classical music while their electrical brain activity (EEG) was measured. Nick
then compared foxtrot dancers' EEG alpha activity to that of tango dancers'. He found that tango
dancers had more alpha activity in the brain than foxtrot dancers.
Is Nick's method correlational or experimental? If experimental, what design? Correct Answer:
Correlational (no random assignment, no manipulation of the IV)
Which of the four validities should you focus most on, when interrogating experiments? Correct Answer:
Internal Validity (Did the IV really cause the difference in the DV?)
Some threats: regression (not as extreme over time), attrition (participant # decreases across testing),
testing (order effect), instrumentation (measuring device effectiveness declines); observer bias
(expectations impact interpretations), demand characteristics (when participants figure out the aim of
the experiment), placebo effects (the expectation of treatment impacts the results)
Dr. Lucas is examining the effect of a talking treatment on hyperactivity in adolescent boys in a local high
school. He randomly samples students from this high school and measures their hyperactivity using self-
report tests. Dr. Lucas then engages this group in his talking intervention for 2 hours a week every week
for 6 months and measures hyperactivity again. He finds that his group is less hyperactive than 6 months
before. Is there a threat to internal validity present? If so, which threat? Correct Answer: Maturation
(due to a change in behavior that emerges spontaneously over time. e.g. kids behavior improved on its
own)
Regression, maturation, history, testing and placebo effects are all threats to internal validity that can be
addressed by adding a ________. Correct Answer: Comparison group
This threat to internal validity occurs systematically and affects most members of the group due to an
external factor/event. Correct Answer: History Threat
The possibility that a third variable is the reason for the relationship between x and y is a problem for
the relationship between x and y is a problem with what type of validity? Correct Answer: Internal
Validity
Intelligence is related to SAT score, but the relationship is actually due to SES.
What is a bivariate correlation and what type of claim is usually made from them? Correct Answer: A
bivariate correlation is an association between two variables. Associational claims are made from
bivariate correlations.
What is the relationship between moderators and external validity? Correct Answer: When
generalizability is affected by moderators, your association may not generalize to all groups of people
Lisa finds a strong positive correlation between impulsivity and rash decision-making.
r = 0.8, p < 0.05.
It turns out there were several pathological gamblers in her sample. Pathological gamblers score
unusually high on impulsivity measures. When she takes these people out, what will happen to the
correlation? Increase or decrease? Correct Answer: Decrease. Removing the outliers will weaken the
correlation.
What are the three rules for causal claims? Correct Answer: Temporal precedence - IV comes before
DV.
Covariance - As A changes B changes.
Internal validity - there is no third variable that describes the relationship (cannot tell from associational)
What type of research design involves measuring the same variables, from the same people, across
different time points? There is no manipulation involved. Correct Answer: Longitudinal
When a relationship between two variables depends on the level of a third variable, that kind of third
variable is called a _________? Correct Answer: Moderator
(Effect is stronger in one subgroup v. another)
Autocorrelation: The association of the variable with itself across time Correct Answer: This diagram
illustrates what kind of correlation?
Cross-Lag Correlation: The association of an earlier measure of one variable with the later measure of
another variable Correct Answer: This diagram illustrates what kind of correlation?
As sleep increases, exam scores increase, even after controlling for time studying and age Correct
Answer: Dr. Bazinga conducts a study examining whether there is a link between exam scores and
sleep. But, he wants to see if any other variables (time studying, age) can explain the relationship. How
might you interpret the result of sleep?
This method assigns people to groups in experiments. It ensures that features of people are 'equated'
except on the independent variable. Correct Answer: Random assignment
, __________ is a simple study that uses a separate group of participants that is generally completed
before conducting the study of primary interest in order to confirm the effectiveness of a manipulation
Correct Answer: A pilot study
Eric designs a study to examine drink preferences of university freshmen. In the study, all participants
drink a cup of coffee then rate their enjoyment of the coffee, then drink a cup of tea and rate their
enjoyment of the tea, and finally drink a cup of milk and rate their enjoyment of the milk. Eric tells
Theresa about the plans for his study and she says she is concerned that he could have a problem of ___
effect in his study. How can Eric fix this problem? Correct Answer: Order effect
Counterbalancing (presenting levels of the IV to participants in different orders)
In a business class experiment on the endowment effect, Theo is comparing the value of a coffee mug to
someone who owns it and is selling it to someone who is buying it. The endowment effect is the
tendency of sellers to value something they own more than buyers do. Participants are randomly
assigned to be buyers or sellers of a mug with their first name on it. Buyers select the maximum price
they would pay for the mug. Sellers select the minimum price they would accept for the mug. Theo then
compares the buyers' and sellers' prices. What kind of design is this? Correct Answer: Posttest only
Expert dancers in foxtrot and tango were recruited from dance studios and participated in Nick's study.
Their task was to listen to classical music while their electrical brain activity (EEG) was measured. Nick
then compared foxtrot dancers' EEG alpha activity to that of tango dancers'. He found that tango
dancers had more alpha activity in the brain than foxtrot dancers.
Is Nick's method correlational or experimental? If experimental, what design? Correct Answer:
Correlational (no random assignment, no manipulation of the IV)
Which of the four validities should you focus most on, when interrogating experiments? Correct Answer:
Internal Validity (Did the IV really cause the difference in the DV?)
Some threats: regression (not as extreme over time), attrition (participant # decreases across testing),
testing (order effect), instrumentation (measuring device effectiveness declines); observer bias
(expectations impact interpretations), demand characteristics (when participants figure out the aim of
the experiment), placebo effects (the expectation of treatment impacts the results)
Dr. Lucas is examining the effect of a talking treatment on hyperactivity in adolescent boys in a local high
school. He randomly samples students from this high school and measures their hyperactivity using self-
report tests. Dr. Lucas then engages this group in his talking intervention for 2 hours a week every week
for 6 months and measures hyperactivity again. He finds that his group is less hyperactive than 6 months
before. Is there a threat to internal validity present? If so, which threat? Correct Answer: Maturation
(due to a change in behavior that emerges spontaneously over time. e.g. kids behavior improved on its
own)
Regression, maturation, history, testing and placebo effects are all threats to internal validity that can be
addressed by adding a ________. Correct Answer: Comparison group
This threat to internal validity occurs systematically and affects most members of the group due to an
external factor/event. Correct Answer: History Threat
