AP Psychology
Name____________________________
Correlation, Experiment, or Quasi Experiment?
Learning Target: Differentiate between types of research (e.g., experiments, correlational studies).
Directions: Read the following studies and determine if they were conducted using a correlational, experimental, or
quasi-experimental design.
1. Indicate the method for each example.
2. List corresponding components of each respective method of research.
● For Experiments identify: IV; DV; Control Group; Experimental Group; Indicate how random assignment
was accomplished
● For Correlational studies identify: First variable; Second variable; Direction of relationship
● For Quasi-experiment identify: IV; DV; Why this example is NOT a true experiment
Hint:
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If a study does not have at least one control and experimental group and RANDOM ASSIGNMENT – it is not an
experiment
RANDOM ASSIGNMENT is required for experiments and allows for CAUSE AND EFFECT
The DV from each of the groups in an experiment are compared to determine if the IV causes the DV
In correlational studies there must be two variables being compared across the same participants, and both
variables must be measurable.
Studies
1. A study by the National Institute on Drug Abuse (NIDA) used PET brain scans to look at the activation
of nicotine receptors in the brains of teenaged nonsmokers who stated they were exposed to secondhand
smoke in their actual lives. The teens filled out questionnaires that indicated how many hours of second
hand smoke they were exposed to during an average week. The participants were given brain scans, and
the amount of nicotine receptor cell activation was measured. The researchers saw that the greater the
level of self-reported exposure to secondhand smoke the higher the levels of nicotine cell activation was
present. This research may indicate that secondhand smoke exposure could prepare young people’s
brains for nicotine; making it more likely they will become addicted if they choose to smoke.
Method:
Components:
2. Researchers collected t-shirts worn over three consecutive nights by 60 volunteers and 60 brand new tshirts, which had never been worn. 120 participants were arbitrarily placed into one of two conditions. 60
participants were asked to rate to smell the shirts that had been worn for 3 nights, and guess how the
‘donors’ rated on the “Big Five” personality traits (openness to experience, conscientiousness,
agreeableness, extraversion and neuroticism). 60 other participants were asked to respond to the smells
of shirts that had not previously been worn and rate how the donors (in this case they were deceived
because these shirts were never worn) would score on the “Big Five” traits. The rater’s who smelled the
shirts, which had been previously worn, were able to predict the donor’s rating on the “Big Five” traits
(previously tested) through smell above the level of chance (European Journal of Personality, Oct., 2011).
Method:
Components:
1
AP Psychology
Name____________________________
3. Psychologists recruited 70 healthy adults and asked them to indicate if they had musical training or not.
The participants all had similar levels of education and academic achievement. Researchers administered
cognitive tests that measured memory, object naming and the ability to learn new information to both the
musicians and non musicians. Musicians scored on average 3 points higher than the non-musicians on
each of the cognitive tests. (Neuropsychology, Vol. 25, No. 3, 2011).
Method:
Components:
4. In research conducted at the University of California Los Angeles, scientists studied 59 adult
participants to determine if a computerized memory program would improve cognitive skills. The
participants used a computerized memory-training program 12 times a month for six-months. The
researchers found that the participants significantly improved in memory and language skills over the sixmonth period. (American Journal of Geriatric Psychiatry, June 2012).
Method:
Components:
5. In research conducted by psychologists at Duke University, participants were asked to provide
information about their knowledge of the nation’s natural resource management by rating themselves on a
scale of 1-10. The participants then read a statement declaring that the United States has less than 40
years’ worth of oil. After reading the statement the participants were given a test called the Need for
Cognition Scale on which they received a score. Those who said they felt unknowledgeable about the
U.S. oil supply not only avoided the negative information about the issue; they became even more
reluctant to know more about the topic when rated on a need for cognition scale. (Journal of Personality
and Social Psychology: Nov 7, 2011).
Method:
Components:
2
AP Psychology
Name____________________________
6. Rena Wing, PhD, director of the Weight Control and Diabetes Research Center studied more than
3,000 overweight people over a 10-year period. Each day participants in the program were required to list
what they ate in a food journal. At the end of the study the researchers computed the total amount of
weight gain or loss. These individuals who all took part in the food journal program lost and average or 14
pounds and reduced the risk of developing type 2 diabetes by 58%. (Unpublished)
Method
Components:
7. Researchers used a randomly selected sample of 1000 sixth graders and found based on survey data
that the more hours of television that the children watched the lower their grades were on annual
standardized tests.
Method:
Components:
8. First time mothers who focused mindfully on the emotional and physical changes brought on by
pregnancy had healthier newborns than mothers who did not practice such mindfulness. In a random
sample of pregnant women chosen by Harvard University, future mothers who were placed by chance
either to be trained in mindfulness (focusing ones thought on subtle changes in feelings and physical
sensations each day) or to receive no training. These women who received the mindfulness training had
healthier newborns as measured by the babies’ growth and weight gain during the 6 months after birth.
(Unpublished)
Method:
Components:
3