Taster 1 preferes A, Taster 2 Prefers B, . In a study of effect of sex on attitudes, the pairs might be husband and wife. In the sunburn example, decide by coin toss, separately for each subject, which side gets the lotion, which the placebo. In the airplane throw, randomly decide, separately for each thrower, which airplane is thrown first.
Sign test is insensitive to wild data since neither averages nor standard deviations are used.
Reject the null hypothesis if the confidence interval for the median does not include 0. In the paper airplane example, the distance flown by the heavy plane exceeded the distance flown by the light plane is shown below for each of 10 throwers. The null hypothesis is not rejected.