PSY 3213 Final Exam | 60 Questions with 100%
Verified Answers
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?
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?
Correlational (no random assignment, no manipulation of the IV)
Which of the four validities should you focus most on, when interrogating experiments?
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?
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 ________.
Comparison group
This threat to internal validity occurs systematically and affects most members of the
group due to an external factor/event.
History Threat
Nicole is comparing high-impulsive and low-impulsive people on a gambling-like task. She
finds that high-impulsives tended to take more risks than low-impulsive people. It turns
out that most people who signed up on SONA during the last two weeks of the semester
were high-impulsives; early birds were low-impulsives. What kind of threat is present?
Selection Threat (the two IV groups are systematically different from each other on something
other than the IV)
How many independent variables does the following design have: 3 X 2 X 2
3
Verified Answers
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?
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?
Correlational (no random assignment, no manipulation of the IV)
Which of the four validities should you focus most on, when interrogating experiments?
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?
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 ________.
Comparison group
This threat to internal validity occurs systematically and affects most members of the
group due to an external factor/event.
History Threat
Nicole is comparing high-impulsive and low-impulsive people on a gambling-like task. She
finds that high-impulsives tended to take more risks than low-impulsive people. It turns
out that most people who signed up on SONA during the last two weeks of the semester
were high-impulsives; early birds were low-impulsives. What kind of threat is present?
Selection Threat (the two IV groups are systematically different from each other on something
other than the IV)
How many independent variables does the following design have: 3 X 2 X 2
3
