Binary, Ordinal, and Categorical Data Analysis - Agricultural Statistical Data Analysis Using Stata - page 225

Wilcoxon signed-rank test
sign | obs sum ranks expected
-------------+---------------------------------
positive | 7 47.5 27
negative | 2 6.5 27
zero | 1 1 1
-------------+---------------------------------
all | 10 55 55
unadjusted variance 96.25
adjustment for ties -0.25
adjustment for zeros -0.25
----------
adjusted variance 95.75
Ho: yield = 2
z = 2.095
Prob > |z| = 0.0362
The median for this dataset is 2.35 t/ha with a probability > |z| of
0.0362, which indicates the median is significantly different from the
2.0 t/ha of the standard linseed variety. This example also shows that
this test ( signrank ) is more powerful than the Sign Test ( sign-
test ), which has a probability of 0.1797 for the same dataset.
Like the Sign Test, the Wilcoxon's Signed Rank Test also can be
used with paired data. With the dataset Fungi Paired Test.dta, enter
the following command and see the results:
signrank fungusa = fungusb
Wilcoxon signed-rank test
sign | obs sum ranks expected
-------------+---------------------------------
positive | 3 11.5 27
negative | 6 42.5 27
zero | 1 1 1
-------------+---------------------------------
all | 10 55 55
unadjusted variance 96.25
adjustment for ties -0.25
adjustment for zeros -0.25
----------
adjusted variance 95.75
Ho: fungusa = fungusb
z = -1.584
Prob > |z| = 0.1132