Point Estimates and Confidence Intervals for the Parameters of the Two-Sample and Matched-Pair Combined Tests for Ranks and Normal Scores.
Abstract Point-estimate and confidence-interval procedures are proposed for (a) the combined Mann-Whitney U test, (b) the combined two-sample normal-scores test, (c) the combined matched-pair Wilcoxon signed-ranks test, and (d) the combined matched-pair normal-scores test. These methods take advantage of the correlation between the blocking variable and the dependent variable under study to improve statistical power. For the combined Mann-Whitney U and the combined matched-pair Wilcoxon signed-ranks method, both exact and approximate procedures are presented, and exact critical values are tabled for a number of small sample size cases. For the combined two-sample and matched-pairs normal-scores methods, approximate procedures are provided. All four techniques are illustrated with hypothetical examples.