For the paired-samples t test, the comparison distribution:
A) is the same as that for a single-sample t test.
B) is the same as that for the z test.
C) contains sample means based on samples of the same size.
D) contains means of difference scores.

Question

Quizplus · Accepted Answer

The comparison distribution for the paired-samples t test contains means of difference scores between two sets of scores, which are essentially the same individuals measured twice. Therefore, the correct answer is D - the comparison distribution contains means of difference scores. A is incorrect because the comparison distribution for a single-sample t test is based on a theoretical distribution, whereas the comparison distribution for a paired-samples t test is based on observed means. B is incorrect because the comparison distribution for a z test is based on a normal distribution with a known variance, whereas the comparison distribution for a paired-samples t test is based on a t-distribution with an estimated variance. C is incorrect because the samples used to calculate the means in the comparison distribution are not necessarily the same size; they simply reflect the differences between the two sets of scores.

For the Paired-Samples T Test, the Comparison Distribution