Psychological Research Methods Flashcards

A researcher uses snowball sampling to recruit participants. This method is most appropriate when:

Answer: The target population is hidden or hard to reach

Snowball sampling, where participants recruit other participants, is useful for hard-to-reach or stigmatized populations.

Which of the following best describes a mediating variable?

Answer: A third variable that explains the mechanism between X and Y

A mediator explains the process or mechanism by which an independent variable causes a change in the dependent variable.

In meta-analysis, what is publication bias?

Answer: The tendency to publish only studies with positive or significant results

Publication bias occurs because journals favor statistically significant results, causing the literature to overrepresent positive findings.

A Type II error in hypothesis testing occurs when a researcher:

Answer: Fails to reject a false null hypothesis

A Type II error (false negative) means failing to detect a real effect — the null hypothesis is false but the researcher does not reject it.

Which ethical principle requires that researchers treat all participants fairly and distribute research benefits and burdens equitably?

Answer: Justice

The principle of justice requires fair selection of participants and equitable distribution of research risks and benefits across groups.

A correlation of r = –0.72 between stress and academic performance indicates:

Answer: High stress tends to co-occur with lower performance, but causation is not established

Correlation shows direction and strength of association but does not prove causation; r = –0.72 is a strong negative relationship.

An operational definition in research refers to:

Answer: The specific, measurable procedure used to define a variable

An operational definition specifies exactly how a variable will be measured or manipulated in a particular study.