Correlation/Regression

  • I tried to fit a line to estimate how many people fall per banana peel, but it was a slippery slope.

    Larry Lesser and Dennis Pearl

  • Lyrics & Music © 2014 Greg Crowther

    If every gal I’ve met is a hypothesis
    Who might turn out to be the mate I’ve sought,
    And if I were to yield
    To the conventions of my field,
    Then you would be referred to as H-naught...

    CHORUS:
    You’re my null, after all; you’re a theory in the making,
    So robust to every test -- my hypothesis of choice.
    You account for the past; you’re a vision of the future;
    And when I feel confused, you’re my signal through the noise.

    My life has been an uncontrolled experiment --
    A source of all too many scattered plots.
    But you provide a line
    With an R-squared of point-nine;
    Yes, you and you alone connect my dots...

    CHORUS

    One can never prove a null
    In a finite length of time;
    Each finding simply strengthens it or not.
    But if I see trends emerge --
    And let’s just say I do --
    I’d be crazy not to publish what I’ve got...

    CHORUS [twice]

  • Lyric © 2015 Lawrence M. Lesser; Music by Dominic Dousa

    Before you do regression,
    Check out the scatterplot 
    Make sure a linear relationship
    Is good for what you've got!

    We try to predict weight
    Using height as the predictor
    If the correlation is really strong,
    We will be a victor!

    For a unit increase of height 
    The expected weight will go
    Up by five units:
    That's the meaning of the slope!

    If r equals 0.9
    then 0.81 is r square:
    The part of variation
    In Y that X does share!

    X and Y
    Have a relationship
    And our well-fit line
    Gives us a good model to predict!

  • Lyric © 2015 by Lawrence Mark Lesser
    may sing to tune of "Twinkle, Twinkle, Little Star"

    How do shoe length values go
    When height is high or when it's low?
    Like horses on a merry-go-round
    When they're both up or they're both down,
    This provides an illustration of a positive correlation!

    How do used car prices go
    When mileage is high or low?
    Like horses on a merry-go-round
    Where one is up when the other's down,
    This provides an illustration of a negative correlation!

    How do weights of people go
    When IQ score is high or low?
    Wild horses on a merry-go-round:
    No pattern to the up or down.
    This is an illustration of zero correlation!

  • Music and Lyrics © 2016 Monty Harper

    OPENING CHORUS:
    Correlation does not imply causation
    Correlation does not imply causation

     

    People who own goggles are often getting fit
    We seem to see that happen quite a lot
    May we conclude that getting fit is caused by owning goggles?
    Clearly, we may not!
    If we take into account how many people swim,
    It's a factor that confounds the implication,
    For people who swim own goggles and get fit
    And that that explains our wacky correlation!

     

    [REPEAT OPENING CHORUS] 

    I've found that when I'm happy, I often seem to giggle
    Knowing that may really serve me well.
    Or maybe when I giggle, it tends to make me happy?
    How am I supposed to tell?
    The arrow of causation may point left or right or both,
    So here's what I suspect to be the scoop:
    I giggle and I feel happy so I giggle and feel more happy
    So I giggle because I'm in a causal loop!

    [REPEAT OPENING CHORUS] 

    The yearly rate of poverty and the length of my own hair
    Correlate with an r of .99
    I discovered this by accident and I don't know what to do
    With this amazing hair of mine!
    Is there some hidden mystic power built into my hair?
    My professor says it's nothing of the kind.
    It's coincidence my hair length predicts the yearly rate of poverty,
    The universe is just messing with my mind.

    [REPEAT OPENING CHORUS] 

    Post hoc ergo propter hoc is just a fallacy
    You expect a certain melody here, but - that's up to me 

    [REPEAT OPENING CHORUS 2X] 
  • Last year, my goofy cat picture went viral - but now it barely gets more hits than my other posts.  Must be regression to the meme.

    Larry Lesser and Dennis Pearl

  • Lyric © 2017 Lawrence M. Lesser
    may be sung to the tune of “Slip Slidin’ Away” by Paul Simon

    CHORUS: Slip slidin’ to the mean, slip slidin’ to the mean,
    You know the less your correlation, the more you’re slip slidin’ to the mean.

    Well parents have daughter or son—
    Their heights were all observed by England’s Francis Galton:
    Extreme parents he did see
    Had kids that regressed toward mediocrity!

    (Repeat Chorus)

    And I know a teacher who gave high praise
    To the students whose midterms were the highest As;
    Those failing badly received rebuke—
    But the next test showed those extremes were a partial fluke!

    (Repeat Chorus)

    And I know a rookie who made the All-Star team
    And the cover of Sports Illustrated magazine.
    You can imagine what the coach thinks
    When the star has sophomore slump as if there was a jinx!

    (Repeat Chorus)

    Watch the video

  • Lyrics © Mary McLellan
    may sing to the tune of Adele's "Hello"

    Slope.Varies.
    It’s the standard deviation of the slope
    You need to know

    Slope.Varies.
    It’s the standard deviation of the slope
    You need to know

    If you sample many times
    I’d expect the slope you find
    Of the relation between X and Y
    To vary this much
    On average over time.

    If you sample many times
    I’d expect the slope you find
    Of the relation between X and Y
    To vary this much
    On average over time.

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