by Gill Marjorie Onate and Muzaffar Bhatti
University of Toronto Mississauga
Five, lucky, randomly chosen married couples.
They were pink elephants, may I add,
Were invited to the party of a lifetime,
They were good looking, not too bad.
But one couple looked different,
Shorter than all the rest.
Everyone called them “the outliers,”
Even so, they looked their best!
There may be a deviation from normality,
Hmm… In what way?
Only five lucky couples were chosen,
Therefore, a small sample size and “the outliers,” I would say!
The effect may be bigger. Should we rely on The Central Limit Theorem?
Along the path, they walked and walked,
Facing a fork up ahead.
“Which way should we go?” They talked and talked,
One elephant looked at the sign and read…
“To make it to the Wilcoxon Signed Rank Test Party,
You must pass this riddle:
Does height have over 20 possible values???
Pick quick, or you’re stuck in the middle.”
Left is “Yes” and right is “No”
“Hmm.. what’s the answer though?”
Pink elephants come in all different sizes!
Sizes come in all!
Big or small,
Short or tall!
Going left would be the right call!
Another sign at the fork up ahead,
“Oh boy, I’m nervous,” one said.
“Are the samples paired???
Yes or No?”
Of course they’re paired!
They’re all married, can’t you see?
“Let’s follow the ‘Yes’ path! It leads us to the Wilcoxon Signed Rank Test Party!”
“Yup, I agree!”
What would have happened if we went down the “No” path?” one asked.
“It means we’re not paired, silly!
At the end of that path is the Wilcoxon Rank Sum Test.
It’s for the ones who are single
And ready to mingle!”
After long walks,
And after long talks,
They made it, finally!
Look at all the clocks!
It’s time! Get ready!
The countdown is starting,
“Woohoo! This is the best!”
HAPPY WILCOXON SIGNED RANK TEST