1. Example 8.1.1: Paired Design Doctors studying healthy subjects measured myocardial blood flow (MBF) during bicycle exercise before and after giving the subjects a dose of caffeine that was equivalent to drinking two cups of coffee.

2. Example: Paired Hypothesis Testing A researcher wants to know how the temperature affects the number of bristles on each fruit flies. The difficulty is that she has 12 fruit flies from 6 different lines (2 of each) and there is no reason to expect that the different lines of fruit flies will have the same number of bristles. She thinks that the bristle number has approximately a normal distribution, but the flies from the same line should have similar bristle numbers.

3. Example: Paired Hypothesis Testing (cont) ColdWarmDifference Liney1y1 y2y2 d = y 1 – y 2 12425 24140 34446 43031 52831 643 mean s SE

4. Example: Paired Hypothesis Testing (cont) ColdWarmDifference Liney1y1 y2y2 d = y 1 – y 2 12425 241401 34446-2 43031 52831-3 643 0 mean s SE

5. Example: Paired Hypothesis Testing (cont) ColdWarmDifference Liney1y1 y2y2 d = y 1 – y 2 12425 241401 34446-2 43031 52831-3 643 0 mean3536 s8.678.191.41 SE3.543.340.58

6. Paired tests: Summary

7. Table 7: Critical values for Sign Test

8. Example 8.4.1*: Sign Test Skin grafts are applied to both sides of the body in 11 recipients. One graft has a close HL-A match with the recipient; the other does not. Observe the time it takes to reject each skin graft. Does a good HL-A match increase graft survival time with a significance of  = 0.05?

9. Example 8.4.1*: Sign Test (cont) HL-A Compatibility ClosePoorSign of PatientY1Y1 Y2Y2 d = Y 1 – Y 2 13729 21913 357+15 49326 51611 62318 72026 86343 92918 1060+42 111819

10. Example 8.4.1*: Sign Test (cont) HLA Compatibility ClosePoorSign of PatientY1Y1 Y2Y2 d = Y 1 – Y 2 13729+ 21913+ 357+15+ 49326+ 51611+ 62318+ 72026- 86343+ 92918+ 1060+42+ 111819-

11. Example: Before-after studies vs. Control