Use of a t-statistic as an approximation to the exact distribution of the wildcoxon signed ranks test statistic
- 1 January 1974
- journal article
- research article
- Published by Taylor & Francis in Communications in Statistics
- Vol. 3 (8) , 795-806
- https://doi.org/10.1080/03610927408827178
Abstract
An approximation to the exact distribution of the Wilcoxon signed ranks test statistic based on the one-sample t-test applied to ranks is compared with the usual normal approximation. A second approximation based on a linear combination of the normal statistic and the t-statistic is introduced. The normal approximation tends to result in a conservative test in the tails, while the Student's t approximation tends to be liberal. The average of the two statistics provides a test that usually has an alpha level as close as possible to the α-levels .05, .025, .01 and .005, for values of n < 50 (only cases examined).Keywords
This publication has 2 references indexed in Scilit:
- Extended Tables of the Wilcoxon Matched Pair Signed Rank StatisticJournal of the American Statistical Association, 1965
- An Approximation for the Exact Distribution of the Wilcoxon Test for SymmetryJournal of the American Statistical Association, 1964