Research Methods
A psychologist observes students interacting in the cafeteria without interfering. What research method is being used?
Naturalistic Observation
Explanation: The psychologist observes behavior in a natural setting without manipulating variables.
In an experiment, what do psychologists call the variable they deliberately manipulate?
Independent variable (IV).
Explanation: The IV is the condition the researcher changes.
As study hours increase, exam scores tend to rise. Is this a positive or negative correlation?
Positive correlation
Explanation: Both variables tend to move in the same direction.
What do psychologists call the entire group of individuals they want to study or draw conclusions about?
Population
Explanation: The population is the larger group of interest.
A researcher defines stress as a score on a 10-question stress questionnaire. What research concept is being demonstrated?
Operational definition
Explanation: The researcher specifies exactly how stress is measured.
A researcher asks 500 students to complete a questionnaire about their sleeping habits. What research method is being used?
Survey
Explanation: A survey collects self-reported information from participants.
In an experiment, what do psychologists call the outcome they measure?
Dependent variable (DV)
Explanation: The DV is the measured result.
As the number of hours students sleep increases, their reported fatigue decreases. Is this a positive or negative correlation?
Negative correlation.
Explanation: The variables tend to move in opposite directions.
What is the difference between a population and a sample?
The population is the entire group of interest; the sample is the smaller group actually studied.
Explanation: Researchers use samples to learn about populations.
Participants are told about the procedures and possible risks of a study before agreeing to participate. Which ethical principle is being followed?
Informed consent
Explanation: Participants receive relevant information before voluntarily agreeing.
A psychologist studies one patient with a rare brain injury over several years. Which research method is being used?
Case study
Explanation: A case study involves an in-depth investigation of one individual or a small group.
Students are assigned to study for either 15 or 30 minutes. Researchers measure their quiz scores. Identify the IV and DV.
IV: Study duration (15 or 30 minutes). DV: Quiz score.
Explanation: The researcher changes the study time and measures performance.
A researcher finds a correlation coefficient of +0.85 between practice time and performance. Is this relationship strong or weak, and positive or negative?
Strong positive correlation
Explanation: The coefficient is positive and close to +1.
What is the difference between random sampling and random assignment?
Random sampling determines who is selected for a study; random assignment determines which experimental condition participants enter.
Explanation: Sampling helps with representativeness; assignment helps create comparable groups.
A psychologist randomly assigns students to an exercise group or a no-exercise group. Why is random assignment important?
It helps make groups comparable by reducing systematic preexisting differences
Explanation: This strengthens the ability to make causal inferences.
A psychologist randomly assigns students to study with music or in silence, then measures how many words they remember. Identify the research method and explain why.
Experiment.
Explanation: The researcher manipulates the study condition and measures its effect on memory.
A researcher assigns participants to drink caffeinated or caffeine-free beverages and measures reaction time. Identify the IV and DV
IV: Beverage condition (caffeinated or caffeine-free). DV: Reaction time.
Explanation: The beverage condition is manipulated, while reaction time is measured.
Which represents the strongest linear correlation: +0.25, −0.90, +0.60, or −0.10?
−0.90
Explanation: Correlation strength is determined by the absolute value, not the sign.
A music group takes a memory test in a quiet classroom, while the no-music group takes the same test in a noisy cafeteria. What is the confounding variable?
The testing environment or background noise.
Explanation: The environmental difference could affect memory independently of music.
A participant decides to stop participating in an experiment without being penalized. Which ethical right is being demonstrated?
Right to withdraw
Explanation: Participants can discontinue participation without penalty.
Researchers find that students who exercise more report lower stress levels. They conclude exercise causes lower stress. What is wrong with this conclusion?
Correlation does not establish causation
Explanation: Other variables or reverse causation could explain the relationship.
A psychologist compares students who sleep 6 hours versus 8 hours and measures the number of words they remember. Explain how memory could be operationally defined.
Memory could be defined as the number of words correctly recalled from a specified list after a set period.
Explanation: An operational definition explains exactly how a variable is measured.
A researcher finds that teenagers who spend more time on social media report higher anxiety. Explain TWO reasons the researcher cannot conclude that social media causes anxiety.
Possible third variables and reverse causation
Explanation: Other factors may influence both variables, and teenagers experiencing anxiety might use social media more.
DAILY DOUBLE!
A psychologist wants to study all NYC high school students but surveys only 20 students from one AP Psychology class. Identify the sampling problem and explain how to improve the study.
The sample is too narrow and may not represent NYC high school students. Recruit a broader sample from multiple schools, preferably using random selection.
Explanation: A more representative sample supports stronger generalization.
DAILY DOUBLE!
A researcher randomly assigns 80 students to exercise for 20 minutes or sit quietly for 20 minutes, then measures stress using a questionnaire. Identify the research method, IV, DV, and one possible limitation.
Method: Experiment. IV: Exercise versus quiet rest. DV: Stress questionnaire score. Limitation: The students may not represent a broader population.
Explanation: The experiment can investigate causal effects, but generalizability depends on how participants were recruited.