Research Design
Name the research method in which a psychologist studies one individual in great detail, often using medical and developmental history
What is a case study?
What does a correlation coefficient measure?
Direction and strength of relationship between two variables
In an experiment, what is the variable that the researcher manipulates called?
Independent variable
Which ethical principle requires researchers to explain the true nature of a study to participants after deception has been used?
Debriefing
Define "population" as used in research methods
The complete set of cases from which a sample may be drawn (e.g., all high school students).
Define a Quasi Experiment
Quasi Experiment is an experiment where there is no independent factor being manipulated
If two variables have a correlation of +0.85, what does that say about their relationship? State direction and strength
Strong positive relationship; as one variable increases, the other tends to increase.
What is random assignment and why is it used in experiments?
Random assignment places participants into conditions by chance to reduce preexisting differences between groups.
Name the committee or board that reviews research proposals to ensure ethical treatment of human participants.
Institutional Review Board (IRB)
What is an operational definition?
Operational definition: specific procedures used to measure or manipulate a concept
Define naturalistic observation and give one strength and one limitation of this method.
Naturalistic observation: observing behavior in real-world settings without intervention. Strength: high ecological validity. Limitation: limited control over variables
Which numeric correlation from this set is strongest: +0.10, –0.67, –0.10, +0.59? Explain briefly
–0.67 is strongest (magnitude 0.67)
Define placebo and explain how a placebo helps control for experimenter or participant expectations
Placebo is an inert treatment given to control group to mimic the experimental procedure and control expectancy effects.
A psychologist surveys 500 female high school students about eating habits. Identify the sample and the population from this example.
Sample: 500 female high school students. Population: all female high school students (in the targeted region/districts if specified)
Define reliability in the context of observational research and give one way to improve it
Reliability: consistency of measurement. Improve by training observers, using clear rubrics, or multiple raters.
A psychologist records behaviors across different classrooms at different times without interacting. What methodological issue must they guard against to ensure observations are consistent across observers?
What is reliability
Explain the difference between statistical significance (p-value) and practical significance. Give an example where p < .05 might still be practically unimportant
p-value shows likelihood results are due to chance; practical significance considers effect size and real-world impact. Example: very small effect in large N can be statistically significant but negligible practically.
Explain the double-blind procedure and state one type of bias it reduces.
Neither participants nor experimenters know condition assignments (double-blind) — reduces experimenter expectancy and participant placebo effects.
Explain why informed consent and protection from harm are both necessary
Informed consent: participants agree with knowledge; protection from harm: minimize physical/psychological risks.
Explain what a meta-analysis does and why researchers use it
Meta-analysis: combines results of multiple studies statistically to estimate overall effect size and identify patterns
Describe when a case study is preferable to an experiment, and provide an example scenario relevant to AP Psychology.
When phenomena are rare or complex and not ethically or practically manipulable (e.g., a detailed study of a rare neurological disorder post-stroke).
A study reports a p-value of .13. What can be inferred about the results? Explain in one sentence.
p = .13 > .05: results are not statistically significant; cannot reject null hypothesis; findings may be due to chance.
Identify the independent and dependent variables in this hypothesis: “Students who study a list of terms in the morning recall more terms than students who study the list just before falling asleep.” Then describe one operational definition for the dependent variable.
Independent: time of day (morning vs. night).
Dependent: number of terms recalled. Operational definition example: number of correct terms recalled on a 20-item free-recall test scored immediately after study.
Distinguish between convenience sampling and random sampling. For generalizing results to the population, which is preferable and why?
Convenience sampling draws easily accessible participants; random sampling gives every individual an equal chance.
Random sampling is preferable for generalization because it reduces selection bias.
A scatterplot shows a U-shaped pattern between two variables. Is a linear correlation coefficient appropriate to summarize this relationship? Explain and suggest an alternative analytic approach.
No. Linear correlation summarizes linear relationships; a U-shaped (nonlinear) relationship would be poorly represented by r. Use nonlinear modeling (e.g., quadratic regression) or examine transformation.