Testing

  • by Lawrence Mark Lesser

    When doing hypothesis tests,
    There's no threshold value that's best.
    It's very contrived
    To use point-oh-five
    To say if you should be impressed!

  • Lyrics copyright by Dennis K Pearl
    May sing to the tune of "When I'm Sixty-Four" (Beatles)

    When collecting data, try to be fair
    Many years from now
    Will you still have a null value defined
    Test to construct, with a p to find?
    If I get one ‘n three-quarters for zee
    Would you lock the door?
    Where should p lead you, will you still need me
    When I'm point oh-four?

    If the science changes
    Shouldn’t the test?
    I could work in stages

    Take mu as random, don’t draw me a line
    State your point of view
    Indicate precisely what your mean will say
    Information wasting away
    Give me your posterior, and its form
    changing evermore
    Where should p lead you, will you still need me
    When I'm point oh-four?

  • Lyrics & Music © 2021 Jonathan F. Spencer

    Best Fit Lover

    I built a model to tell me whom to love, trained on data from my youth. My null hypothesis was there was someone else, but could the alternate be truth?

    Where are you, best fit lover? Proven true, significant other. Where are you, best fit lover? Proven true, significant other.

    Method

    I set my alpha well below 0.05, ‘cause why take chances on our fate? I picked predictors, both natural and derived. Scaled and centered every trait.

    Where are you, best fit lover? Proven true, significant other. Where are you, best fit lover? Proven true, significant other.

    Considerations

    You told me of your bias, that I’d never change your mind, but you can't argue with science, see my love is double blind.

    Results

    It was you, best fit lover. Reject the null; there’s no other.

    Discussion

    Where are you, best fit lover? I’ll be true, significant other.

    Conclusion

    It was you, best fit lover. Proven true, significant other. It was you, best fit lover. Proven true, significant other.

  • A sign test has its pluses and minuses but the Wilcoxon does first things first.

    Larry Lesser

  • I was in denial about using a non-parametric test - but the signs were all there.

    Dennis Pearl

  • by Nyaradzo Mvududu

    Two groups in random selection
    The differences under inspection
    On an interval scale
    And a test with one tail
    The hypothesis suffers rejection

  • Students learn the ideas of hypothesis testing in an activity where they guess which of three sodas is the different one.

  • by Lawrence Mark Lesser

    He asks, “How can you mix social justice with teaching statistics?”
    I’m thinking: how can you not?
    How better to illuminate
    deviation from expected values?

    He says, “But it’s not neutral.”
    Like it’s natural and neutral to teach from books
    based on baseball, playing cards, and flatscreen TVs
    rather than view by neighborhood things like

    incidence of asthma or
    incidents of racial profiling.
    We’ve been testing
    a null that dulls 

    by what’s normalized
    as if the type 
    1 error
    is always worse.

    When he says social justice is beyond our scope,
    I want to ask: do you mean
    our discipline or
    our humanity?

     

  • 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? 
    No way!


    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!”

    “Just curious, 
    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!”
    3…2…1!!!

    HAPPY WILCOXON SIGNED RANK TEST

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