Which of the following statements are true?
A) Whenever there is positive dependence within pairs, the denominator for the paired t statistic should be smaller than for t of the independent-samples test.
B) When data is paired, the paired t confidence interval will usually be narrower than the (incorrect) two-sample t confidence interval.
C) If there is great heterogeneity between experimental units and a large correlation within experimental units, a paired experiment is preferable to an independent-samples experiment.
D) If the experimental units are relatively homogeneous and the correlation within pairs is not large, an independent-samples experiment should be used.
E) All of the above statements are true.

Question

Quizplus · Accepted Answer

Each statement accurately reflects principles of statistical testing and experimental design. A) Positive dependence within pairs reduces variability in the difference scores, leading to a smaller denominator in the paired t statistic. B) Pairing reduces variability due to matching, resulting in a narrower confidence interval. C) Pairing is advantageous when there's high variability between units but high correlation within pairs, as it controls for the heterogeneity. D) An independent-samples design is more suitable when units are homogeneous and there's little to no correlation within pairs, as pairing offers no advantage in reducing variability.

Which of the Following Statements Are True