Hello everyone,

I apologize in advance for what must seem like a very obvious question.

When you do a pair analysis of variable in JMP, you can ask the software to perform a Wilcoxon signed rank test which then gives me as a result a test statistics named S.

Question is : **What is S**?

It does not match the sum of all the ranks because it can be a negative

It does not match the sum of the signed ranks or even the half-sum of the signed ranks (and it would be named W not S)

Can someone please share some light on this issue since the JMP documentation only states how to calculate W but doesn't say a word about S ?

Another question : How do i switch from a one-tail test (which is the one performed) to a two tailed test.

I've included the sample data i use. The sum of the positive ranks is 19 and the sum of the negative ranks is 134.

W should be 62.5. S is 68. What am i missing ?

Best regards,