Wilcoxon Signed Ranks Test

Graham Tall   G.E.Tall@bham.ac.uk

Wilcoxon's test uses paired data and is equivalent to the correlated/paired/related t test.  Wilcoxon's test should be used if the standard deviations of the two groups are not comparable.

The test is more powerful than the Sign test  because it uses information on the size of the differences.

An EXCEL spreadsheet ORDINAL.XLS prepared by Graham Tall, is available in the statistics folder in the IT room.   This test can be carried out in SPSS by first selecting:   Analyze, then   Nonparametric Tests  and finally    2 Related Samples...

Tables to assess the significance of the Wilcoxon Signed Rank test and the Sign Test can be found in:

Siegel, S. (1956) Nonparametric Statistics. McGraw-Hill:London
Siegel, S. & Castellan, N.J. (1988) Nonparametric Statistics. McGraw-Hill:London

Home Page   Research Introduction    Quantitative Advice     Index     Statistical Tests    Types of Number           Basic Statistics