Let’s face it. You’re busy. I’m busy. We’re all busy with our business.

In a world that spins at about 1,000 miles per hour, and seems to pick up speed every day , we’re lucky if we have enough time, energy, and focus to put on matching socks in the morning. (Notice that my socks have been cropped from this picture.)

So trying to quickly get a handle on the statistics you need for a quality improvement project can be, at best, a harried proposition.  And it’s easy to find yourself suddenly mired in a gooey swamp of p-values, correlation coefficients, matrix plots, and pooled variances.

Had we...

Despite the mountain of statistics backing the relative safety of air travel, I’m a nervous flyer.

If a plane hits turbulence, I turn a light shade of olive green and start panting like a sick dog. When I look around the plane compartment, everyone else seems bored and unconcerned.

Me? I’m clutching the arm rest, as 10,000 tiny ballerinas turn pirouettes in the pit of my stomach. It’s a visceral reaction that defies logic.

But it doesn’t help when I hear alarming reports, like the one the other week about the close call of two jets landing at the Detroit Metro airport.

The FAA reported that the...

Muntasir Mamun and Mohammad Ujjal are riding across the U.S. on a bicycle built for two.

As they pedal in sync from Seattle to New York, they're not only gazing at our purple mountains’ majesty and amber waves of grain. They’re also keeping their eyes peeled for plastic soda bottles, glass beer bottles, and styrofoam cups!

These self-dubbed “trashmaniacs” are collecting and recording every piece of trash they find on their 5000-mile trip. Their mission? To make us more aware of how the waste that we generate here can have a profound impact in places very far away.

I love what these guys are...

In response to a previous post, a reader asked about the best way to represent variation in data. The reader was specifically asking about error bars, which are sometimes displayed on graphs as standard deviation (SD), standard error (SE), or confidence intervals (CIs).

I'd like to broaden the implications of this excellent question. What does each estimate of variation tell you—and what doesn’t it tell you?

Kick back, put on your headphones, and pour yourself some tea. Let's explore this topic using one of the world's most popular and enduring musical formats—the theme and variations.

(If you're...

Unless you’ve been marooned on a desert island, you've probably been hearing a lot of hullaboo about the Higgs boson particle over the last few days.

Scientists claim they’ve finally proven the existence of this long sought-after “God particle,” which supports the standard model of the universe by identifying the particle that gives mass to other particles like protons and electrons.

If you’re keen on the statistics behind this discovery, you’ll notice that many news articles cite the fact that the scientists are certain of their results at the 5-sigma level, or a 99.9999% level of confidence.

Yo...

The doctor’s advice to beat the heat? Chuck it all and head to the nearest lake, river, or ocean. Stick your bare feet in the cold water, and avoid all strenuous activity—except maybe skipping stones.

Yes, it’s a perfect time to lazily hone your technique and prepare for the upcoming Pennsylvania Qualifying Stone Skipping Tourney. Every year, amateur and professional skippers congregate on the banks of the mighty Allegheny River to compete in this crazy rock-slinging fest, only about 2 hours away by car from Minitab, Inc. 

In fact, the two most recent world record-holders for stone skipping,...

The 2012 U.S. presidential campaign is kicking into high gear. And you know what that means.

Political memes will soon be hatching from their electronic eggs, flying through myriad channels of the media, and buzzing annoyingly in your ears.

Memes are kernels of content that spread rapidly across the internet. Love them or hate them, you can’t deny their proliferation or their impact on our mass consciousness.

Remember the 2008 campaign? Lipstick on a pig? Joe the Plumber?

To explore the dynamic life cycle of memes, researchers at Cornell and Stanford tracked the top memes from the 2008...

The other day I stopped at a fast food joint for the first time in a while.

After I ordered my food, the cashier asked me if I wanted to upgrade to the “Super-Smiley-Savings-Meal” or something like that, and I said, “Sure.”  

When it came, I was astounded to see the gargantuan soda cup. I don’t know how many ounces it was, but you could have bathed a dachshund in it.

If I drank all the Coke that honkin' cup could hold, the megadose of sugar and caffeine would launch me into permanent orbit around Earth.

That huge cup made me think of sample size.

Generally, having more data is a good thing. But if...

In my last blog, we looked at how a single data entry error can cruelly sabotage your statistical analysis.

And if that doesn't scare you silly, maybe this will.

The frequency of data entry errors can be as high as 27%, even when using the conservative "double-entry" method to record each data value twice.

So what can you do? Besides make offerings to appease Ate, the ancient Greek goddess of delusion, folly, and reckless errors?

First, some old-school advice. There’s no substitute for taking a deep breath, rolling up your sleeves, and double-checking every observation in your data.

But suppose...

The demands of modern life can make us very distracted.  

We should all do our best to slow down and not make sally mistakes. But it can be tough.  

With information coming at us from all directions, it's easy to get side-tracked and lose your …um, whatever.

But it's critical to prevent careless erors from creeping into your data. Because if you're not careful, a lot of innocent men may wind up getting pregnant by accident.

At least that's what happened to thousands of British men, who supposedly received gyneocological, obstetric, and other prenatal services over a two-year period, according to a...

I don’t know about you, but I’m thankful we no longer live in a time when we feel compelled to swig swamp-root juice any time we want to feel better. The field of medicine couldn’t advance by relying solely on subjective anecdotes and testimonials, like those for Dr. Kilmer’s cure-all.

Using statistical analyses, we can now objectively evaluate various preventions and treatments in measurable, quantitative ways.

Curious to see what Minitab Statistical Software was up to in healthcare and medicine lately, I ran a Medline search. In the past year, the software has been busy making the rounds,...

If your measurement system depends on subjective decision-making, it’s critical to evaluate its consistency and accuracy.

Lately, I’ve been bottle-feeding my work colleagues skunky and sour beer to see how well they can identify defective grog.  

Now it’s time to evaluate my (hic) go/no-go gage in Minitab using an Attribute Agreement Analysis.

How well did our appraisers do? Let's look at the results from the Minitab Assistant (Assistant > Measurement Systems Analysis > Attribute Agreement Analysis.)

Accuracy of Appraisals

First, the accuracy of all the appraisals taken together:

Overall, our...

I’ve been hiding empty beer bottles in my office lately. I hope no one finds them. My boss is in the next office and he's already asked about the occasional "clinking sounds.” I told him I’m practicing castanets for the Minitab talent show.

But it's not what you think. Inspired by the relationship between beer and statistics, I'm conducting an attribute agreement analysis of beer appraisals. Sometimes, an ice-cold, concrete example is the best way to experience the ins and outs of a statistical analysis.

Suppose that Minitab is a brewery and Release 16-Special Edition is a premium beer. The...

It’s a well-known fact that consumption of beer leads to improved statistical quality analysis.

Before you start pounding beers at your desk to get your p-values lower than alpha, let me explain. It’s a famous story in the history of statistics, and one that bears retelling for St. Patrick’s Day.

A Painstaking Process in the Land of Patricks

In the early 1900s, the Guinness Brewery in Dublin was the largest brewery in the world, churning out about 100 million gallons of beer each year to quench the collective thirst of the globe. Yet this huge production volume was tied to a very finicky brewing...

Poring over a printout of radio signals in the late 1970s, an astronomer at the Big Ear telescope at Ohio State University was flabbergasted to discover what appeared to be a big ole “How-Do-You-Do?” from space aliens, jumping out from the everyday mish-mash of earthly radio signals. He circled the signal and recorded his amazement in the margin in red:

The signal appeared to come from the constellation Sagittarius and lasted 72 seconds. At the time, it generated keen excitement among those searching for intelligent life in the universe and came to be known as the “Wow!” signal.

Does the...

“How do you write your blogs?" someone asked me the other day.

“It’s really simple," I replied. "I just apply the infinite monkey theorem.”

According to the infinite monkey theorem, if enough monkeys type randomly on a keyboard for a long enough time (infinity), they will be almost certain to produce any given text: a play by Shakespeare, the U.S. Constitution, or Minitab Help.

A key premise is the concept of randomness. The monkeys must be equally likely to strike any key of the keyboard. That makes the eventual typing of Hamlet, or any other outcome, theoretically possible with enough...

When you think of design of experiments (DOE), what types of applications come to mind? Do visions of camshafts, widgets, capacitors, resistors, and other industrial thingamabobs dance in your head?  

If so, that's probably because DOE has such powerful and successful applications in manufacturing. Those experiments often involve changing levels of physical factors, such as temperature or pressure or speed or material, and then identifying the settings that produce the optimal effect. 

So a designed experiment can raise the spectre of Dr. Victor Frankenstein in the laBORatory, madly pulling...

The Bickersons Battle Over Alpha

Meet Betty and Bart Bickerson, husband and wife quality analysts who work at different companies.

Betty and Bart argue about everything. They argue whether grey is a color. They argue whether tomato is a fruit. They argue whether the chicken came before the egg, and whether the egg tastes better fried, scrambled, or poached.

But their relationship didn’t get really rocky until they started to argue about what alpha level, also called the significance level, to use for a hypothesis test.

Note: The alpha level is the criterion against which you compare the p-value...

In my last blog, we compared fatality rates on Himalayan peaks to determine which mountain provides the biggest challenge for would-be mountaineers in search of death thrills. 

Of course, if you’re an adventure/trekking company, you have another goal: to guide thrill-seeking mountaineers to the peak safely. You want to protect your customers from experiencing the ultimate defect: death.

So you need a tool to clearly identify the most important problems or causes leading to fatalities on the climbs. That calls for the graphical workhorse of quality improvement analysis: The Pareto Chart (Stat >...

Earlier this month, thousands of trekkers were stranded by bad weather near Mount Everest and had to be evacuated. The news made me wonder: Just how many people are chillin' on Chololungma ( “Holy Mother”—the Tibetan name for Everest) these days?

So I decided to do some exploring of the statistical variety, using Minitab as my trusty Sherpa.

Exploratory analyses are a great way to reveal unexpected characteristics of your process. They just require an open mind, an ability to ask questions, and easy-to-use statistical software.

For example, a time series plot displays observations sequentially...

Are you someone who never imagined you’d be using statistics in your work? Do you feel, at times, like an undercover interloper in the land of p-values, as you step gingerly to avoid statistical land mines with long, complex-sounding names?

For example, do you feel a slight chill run down your spine when you read:

“For your analysis results to be valid, you should ascertain whether your data satisfy the assumption of homoscedasticity”?

Sometimes it’s best to face your fears head on.

Granted, homoscedasticity is definitely not a word you should say in public with a mouthful of beer and mashed...