Communicating statistical concepts quickly and clearly is just as critical as being able to calculate them, so I focus on quick, practical insights about statistics to help you make data-driven decisions. Continue Reading »
Republican or Democrat.
Yin or yang.
Why is it that life often seems to boil down to two choices?
Heck, it even happens when you open the Basic
Stats menu in Minitab. You’ll see a choice between a
2-sample t-test and a paired t-test:
Which test should you choose? And what’s at stake?
Ask a statistician, and you might get this response:
"Elementary, my dear Watson. Choose the 2-sample... Continue Reading
t-test is one of the most frequently used procedures in
But even people who frequently use t-tests often don’t know
exactly what happens when their data are wheeled away and operated
upon behind the curtain using statistical software
It’s worth taking a quick peek behind that curtain.
Because if you know how a t-test works, you can understand what
your results really mean.... Continue Reading
you’re 3 years old, you probably can’t have things just the
way you want them all the time.
You can’t always have peanut butter and ranch dressing
on your toast. Or ketchup on your pineapple. Or sugar sprinkles on
But there is one small arena in life over which you can still
exert your control.
Tools > Options in Minitab's statistical softwareallows you to change selected default... Continue Reading
“Shall I compare thee to a standard normal distribution?
Thou art more symmetric and more bell-shaped…”
— Melvin Shakespeare (William’s lesser-known statistician
The Greek philosopher Aristotle believed that symmetry was one
of the primary elements of the universal ideal of beauty. Over 2000
years later, emerging research seems to bear him out.
Studies suggest we tend to be more... Continue Reading
Using a Survey of Aquatic Bugs to Estimate Stream Quality
we click, flip, and scroll through hundreds of sites and channels,
cruising for our daily dose of e-thrills, it’s easy to forget
there’s a beautiful, wild, creative universe right in our
I had the chance to experience a tiny part of that universe on a
recent Saturday afternoon, when a couple of friends, Yolanda and
Monika, asked... Continue Reading
Patrique Roonquel, guest blogger
Institut Sacre Bleu
I enjoy using Minitab Statistical Software to uncover the vast
causal relationships unfolding in the universe all around
What kind of novel things have I proven with Minitab? Almost
anything you can imagine, mon petite shoe.
For example, the fitted line plot below clearly shows one thing:
it’s time for our political parties to stop all the... Continue Reading
happened to you?
You organize a brainstorming session to begin analyzing your
At the kick-off meeting, several people sit with arms crossed,
lips pursed, eyes cast downward. Frequently, they’re the ones
who’ve worked at the process for most of their professional
“Here we go again. Wasting time to prove the obvious,”
their faces say. “I’ve done my job for years. You’re not... Continue Reading
the title of this post made you think you’d be reading about
Abraham Lincoln and Tyra Banks, you’re only half right.
A few weeks ago, statistician and journalist Nate Silver
published an interesting post on how U.S.
presidents are ranked by historians. Silver showed that the
percentage of electoral votes that a U.S. president receives in
his 2nd term election serves as a rough predictor of... Continue Reading
has been hauled to court for violating the assumptions of
regression analysis. On the last day of the trial, the prosecution
and defense present their closing arguments. And the fate of Mr.
Loosefit is decided by judge and jury...
The Prosecution's Summary
Prosecutor: Ladies and gentlemen, we’ve
presented a slew of evidence in this trial. You’ve seen, with your
own eyes, every... Continue Reading
Lionel Loosefit has been hauled to court for violating the assumptions of linear regression.
On Day 3 of the trial, the court examines the allegation that the
residuals in Mr. Loosefit's model exhibit nonconstant variance. The
defendant’s mother, Mrs. Lottie Loosefit, has taken the stand on
behalf of her son.
Defense Attorney: So, Mrs. Loosefit, from what
you’ve described to us, your son, Lionel,... Continue Reading
Recap: Lionel Loosefit has been arrested
and hauled to court for violating the assumptions of regression
the previous court session, the prosecution presented evidence
to show that the errors in Mr. Loosefit’s model were not normally
distributed. Today, the prosecution addresses the second alleged
violation: namely, that the errors in the defendant’s regression
model are not... Continue Reading
Bailiff: All Rise. The Honorable Judge Lynn E.
R. Peramutter presiding.Judge: Please be seated. Bailiff, please read
the charges.Bailiff: Your honor, this is the case of the State
vs. Lionel Loosefit. The defendant is charged with creating a model
that violated the legal requirements for regression. The
Producing grossly nonnormal errors
Producing errors that lack independence
Exh... Continue Reading
Whenever something suddenly fell apart, my grandfather used to
exclaim “Down goes the meat house!” I don’t know where that
expression came from—as a child I often pictured a
flabby house of raw meat caving in on itself. (This was
decades before Lady Gaga made wearing raw meat
My grandfather’s expression still pops into my head when I think
about a probit analysis.... Continue Reading
butter roasted turkey.
Steaming mashed potatoes.
Tangy cranberry relish.
Delicious candied sweet potatoes.
Creamy green bean casserole.
Sweet and airy corn bread.
Silken pumpkin pie.
The traditional Thanksgiving menu has so many mouth-watering
dishes on the table, you don’t know where to start.
If you savor statistics as much as food, you might feel
similarly as you gaze at all of the delicious ... Continue Reading
been a grueling election campaign for Senator William Overstate, or
Will Overstate, as he is known by his constituents. Senator
Overstate has been running his re-election campaign on a single
issue: to make Election Day a national holiday.
That sounds good to me!
The senator argues that it's difficult for many people to get to
the polls on election day because of work—especially those who
work ... Continue Reading
So what stops
eligible U.S. voters from showing up at the polls on election
day? I’m not going to be able to tease out all the possible
factors associated with variability in voter turnout in one blog
But you can often be forgiven in statistics if you clearly state
at the onset that your main objective is a preliminary exploration
rather than a final, conclusive analysis. So let’s explore.
Do... Continue Reading
Tuesday is the big day.
If you think I mean National Saxophone Day, please remember to put
your sax down on November 6 and go vote! Otherwise, voter
turnout for the election will be nothing to toot your horn
As it is, the percentage of people who turn up at the
polls to vote is much lower in the U.S. than in many other
democracies around the world.
Or is it? Surprisingly, a lot depends... Continue Reading
If you walk along an open field in central Pennsylvania in
September, blaze orange is often the first sign of
approaching fall you'll see. And it happens before the leaves even
begin to turn color.
The annual migration of millions of monarch butterflies in North
America is one of the great wonders of nature. Every
autumn, these delicate beauties flutter from as far north
as Canada to their... Continue Reading
You know the
famous proverb: "Give a man a fish and you feed him for a day.
Teach a man to fish and you feed him for a lifetime."
It's especially true when you're casting your line for
When I first started using Minitab Statistical
Software, it was daunting trying to learn all
of its analysis capabilities. There are hundreds of
commands in the Stat menu alone!
Eventually, I found that... Continue Reading
Sheriff Taylor: Remember the talk we had awhile back about Pp?Barney: Keep talking like a
potty mouth, Andy, and Aunt Bea’s going to wash your mouth out
with soap!Sherriff Taylor (sighs): So you remember that Pp
is the ratio of the specification spread to—Barney (interrupts): —the process spread! Yeah,
yeah, I got all that. And the smaller your car (process
spread), relative to its parking space... Continue Reading
Minitab is the leading provider of software and services for quality
improvement and statistics education. More than 90% of Fortune 100 companies
use Minitab Statistical Software, our flagship product, and more students
worldwide have used Minitab to learn statistics than any other package.
Minitab Inc. is a privately owned company headquartered in State College,
Pennsylvania, with subsidiaries in the United Kingdom, France, and
Australia. Our global network of representatives serves more than 40
countries around the world.