Author Question: Suppose instead of comparing independent measurements taken from two groups, you used a ... (Read 114 times)

nevelica · **on:** Jul 24, 2018

Suppose instead of comparing independent measurements taken from two groups, you used a matched-pairs experiment and one treatment is randomly assigned to each half of the pair. In this case, how should you compute the confidence interval for the difference?
a. Do it the same way you would do it for two independent groups. You'll just get more accurate results because they came from matched pairs.
b. Do a separate confidence interval for each half of the pair and subtract the confidence intervals to get a range of differences.
c. Compute the differences for each pair, treat them as a single data set, and use the formula for a confidence interval for one mean (the mean difference).
d. None of the above.

Question 2

Which of the following is the correct way to calculate the standard error of the difference between two (independent) means? Let SEM1 represent the standard error of the first mean, and let SEM2 represent the standard error of the second mean.
a. SEM1 + SEM2
b. SEM1 SEM2 .
c. The square root of (SEM1)2 + (SEM2)2.
d. The square root of (SEM1)2 (SEM2)2.