- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Get Direct Link
- Report Inappropriate Content
Wilcoxon Sign Ranked Test - JMP OUT PUT
Hi,
So I am doing Wilcoxon Sign Ranked test and I am not understanding what JMP is doing for where it says test statistic. I understand its using the "Pratt method" and this is the formula
S = R+ - 1/4[(N(N+1)-do(do+1)]
but could you expand on this a little further as I am not getting the same thing as what JMP is gettting.
where my values are :
R+ is 1527,
my sample has 76 pairs,
and 11 0's.
I try plugging my values into that formula and I get is but JMP is returning 581 for S. Please help me I am going nuts.
S = 581 does not = 1527-1/4[76(76+1)-11(11+1)]
THANK YOU!!!!!!!!!!!!!!
I should mention when adding these in the matched pair test under analyzed I am putting dad height first then height (which is the opposite of how I want it to read out). Data attached
Rachel
Accepted Solutions
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Get Direct Link
- Report Inappropriate Content
Re: Wilcoxon Sign Ranked Test - JMP OUT PUT
I've done the calculations in a JMP table (attached).
Following the calculation steps in the online documentation:
https://www.jmp.com/support/help/en/15.2/index.shtml#page/jmp/wilcoxon-signed-rank-test.shtml
I get S = -581 (same as JMP)
And for R+ I get 849; plug that into the R+ formula using d0=11, you also arrive at -581.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Get Direct Link
- Report Inappropriate Content
Re: Wilcoxon Sign Ranked Test - JMP OUT PUT
I've done the calculations in a JMP table (attached).
Following the calculation steps in the online documentation:
https://www.jmp.com/support/help/en/15.2/index.shtml#page/jmp/wilcoxon-signed-rank-test.shtml
I get S = -581 (same as JMP)
And for R+ I get 849; plug that into the R+ formula using d0=11, you also arrive at -581.
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Get Direct Link
- Report Inappropriate Content
Re: Wilcoxon Sign Ranked Test - JMP OUT PUT
@David_Burnham wow thank you so much for putting that together for me and showing me!. I greatly appreciate this!!
I finally saw where I was going wrong, my error was with R+!
Curious if you could answer another question for me?
Can you explain to me what the highlighted part of the the variance formula is? I can not wrap my head around the term di.
Thank you,
Rachel
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Get Direct Link
- Report Inappropriate Content
Re: Wilcoxon Sign Ranked Test - JMP OUT PUT
The principle is that the presence of ties will have the effect of reducing the variance, so an adjustment is required by an amount that is a function of the proportions of the observations that are tied at each tie point. However, I'm not familiar with the details of the calculation or the theoretical basis of it.