Wilcoxon Signed Ranks

Specification

• Wilcoxon signed ranks test of difference

The Wilcoxon test is a non-parametric statistical test of difference that allows a researcher to determine the significance of their findings. It is used in studies that have a repeated measures, where the data collected is at least ordinal.

Wilcoxon Signed Ranks test process

• Calculate the difference between two scores by taking one from the other

• Rank the differences giving the smallest difference Rank 1

Note: do not rank any differences of 0 and when adding the number of scores, do not count those with a difference of 0, and ignore the signs when calculating the difference

• Add up the ranks for positive differences

• Add up the ranks for negative differences

• T is the figure that is the smallest when the ranks are totalled (may be positive or negative)

• N is the number of scores left, ignore those with 0 difference

Past Paper Questions

• Determine whether this result is significant or not (Wilcoxon). (1) June 2016

• Explain whether Zulikhat's result is significant or not (Wilcoxon). (2) June 2019

• Complete Table 4 and calculate the Wilcoxon Signed Ranks test. (4) January 2020