Research Methods and Statistics Flashcards

A researcher measures anxiety before and after a treatment in the same group. Which statistical test is most appropriate?

Answer: Paired-samples t-test

The paired-samples (dependent) t-test compares means from two related measurements taken from the same participants.

What does internal validity refer to in psychological research?

Answer: The degree to which changes in the DV are caused by the IV

Internal validity concerns whether observed changes in the dependent variable are genuinely caused by manipulation of the independent variable, ruling out confounds.

Which sampling method gives every member of the population an equal chance of being selected?

Answer: Simple random sampling

Simple random sampling uses a process (e.g., lottery or random number generator) that gives each population member an equal probability of selection.

In APA Publication Manual format, how should a statistically non-significant result be reported?

Answer: p > .05 with actual p-value, e.g., p = .21

APA recommends reporting the exact p-value regardless of significance (e.g., p = .21) rather than only noting p > .05 or 'NS'.

What is the main advantage of a within-subjects design over a between-subjects design?

Answer: It requires fewer participants and reduces error variance

Within-subjects designs use each participant as their own control, reducing individual-difference error and requiring fewer total participants.

Which type of reliability refers to consistency of a measure across different raters?

Answer: Inter-rater reliability

Inter-rater reliability (also called inter-observer reliability) measures the degree to which different raters agree in their assessments or coding.