Research Methods & Psychological Foundations Flashcards

A researcher finds a Pearson r = 0.65 between depression scores and sleep quality. Which conclusion is most appropriate?

Answer: There is a moderate positive relationship between the two variables

A correlation coefficient of 0.65 indicates a moderate positive relationship but does not imply causation.

Which experimental design best controls for history effects in longitudinal research?

Answer: Solomon four-group design

The Solomon four-group design controls for both testing effects and history effects by including groups with and without pretests.

A psychologist uses snowball sampling to recruit participants with a rare phobia. The primary limitation of this approach is:

Answer: Non-random selection leading to limited generalizability

Snowball sampling relies on participant referrals, producing a non-random sample that may not generalize to the broader population.

In signal detection theory, a 'miss' refers to:

Answer: Failing to detect a signal that is actually present

A miss (false negative) occurs when a signal is present but the observer fails to detect it.

Which statistical test is most appropriate when comparing means across three or more independent groups?

Answer: One-way ANOVA

One-way ANOVA is designed to compare means across three or more independent groups while controlling the Type I error rate.

Construct validity is best evaluated by examining:

Answer: The pattern of correlations with theoretically related and unrelated variables

Construct validity is supported through convergent and discriminant evidence—correlating with related measures and not correlating with unrelated ones.

A within-subjects (repeated measures) design increases statistical power primarily by:

Answer: Removing individual difference variance from the error term

Repeated measures designs use each participant as their own control, removing between-subject variability from the error term and increasing power.