we start off 2018, our eyes are on the winter weather, specifically
low temperatures and snowfall. After 2015-2016's warmest winter on record and Chicago breaking records in 2017 with no snow sticking
to the ground in January or February, our luck might have run out.
We shall see, though. The Old Farmer's Almanac is reporting that
2017-2018 winter temperatures will be colder than last winter.
If... Continue Reading
On the heels
of Healthcare Quality Week last week, we wanted
to share our conversation with Dr. Sandy Fogel, the surgical
quality officer at Carilion Clinic in Roanoke, VA.
Although he has been a practicing
surgeon for nearly 40 years, Dr. Fogel’s enthusiasm for quality
improvement makes it sound as if he is just getting started. After
medical school at Washington University in St. Louis and... Continue Reading
California have killed at least 40 people and burned more than
217,000 acres in the past few weeks. Nearly 8,000 firefighters are
trying to contain the blazes with the aid of more than 800
firetrucks, 70 helicopters and 30 planes.
In remote areas difficult to access by firetruck, smokejumpers
may be needed to parachute in to fight the fires. But danger looms
before a smokejumper even... Continue Reading
Overfitting a model is a real problem you need to beware of when
performing regression analysis. An overfit model result in
misleading regression coefficients, p-values,
and R-squared statistics. Nobody wants that,
so let's examine what overfit models are, and how to avoid falling
into the overfitting trap.
Put simply, an overfit model is too complex for the data you're
analyzing. Rather than... Continue Reading
Maybe you're just getting started with analyzing data. Maybe
you're reasonably knowledgeable about statistics, but it's been a
long time since you did a particular analysis and you feel a little
bit rusty. In either case, the Assistant menu in Minitab Statistical Software
gives you an interactive guide from start to finish. It will help
you choose the right tool quickly, analyze your data... Continue Reading
Control charts take data about your process and plot it so you
can distinguish between common-cause and special-cause variation.
Knowing the difference is important because it permits you to
address potential problems without over-controlling your process.
Control charts are fantastic for assessing the stability of a
process. Is the process mean unstable, too low, or too high? Is
observed... Continue Reading
In statistics, as in life, absolute certainty is rare. That's
why statisticians often can't provide a result that is as specific
as we might like; instead, they provide the results of an analysis
as a range, within which the data suggest the true answer lies.
Most of us are familiar with "confidence intervals," but that's
just of several different kinds of intervals we can use to
characterize the... Continue Reading
by Matthew Barsalou, guest blogger
At the end of
the first part of this story, a group of evil trouble-making
chickens had convinced all of their fellow chickens to march
on the walled city of Wetzlar, where, said the evil chickens, they
all would be much happier than they were on the farm. The chickens marched through the night and arrived at Wetzlar on
the Lahn as the sun came up. “Let us in!”... Continue Reading
by Matthew Barsalou, guest blogger
Once upon a time, in the Kingdom of Wetzlar, there was a farm
with over a thousand chickens, two pigs, and a cow. The chickens
were well treated, but a few rabble-rousers among them got the rest
of the chickens worked up. These trouble-making chickens
looked almost like the other chickens, but in fact they
were evil chickens.
By HerbertT -
Eigenproduktion, CC... Continue Reading
The Six Sigma quality improvement methodology has lasted for
decades because it gets results. Companies in every country around
the world, and in every industry, have used this logical,
step-by-step method to improve the quality of their processes,
products, and services. And they've saved billions of dollars along
However, Six Sigma involves a good deal of statistics and data
analysis,... Continue Reading
Six Sigma is a quality improvement method that businesses have
used for decades—because it gets results. A Six Sigma project
follows a clearly defined series of steps, and companies in every
industry in every country around the world have used this method to
resolve problems. Along the way, they've saved billions of
But Six Sigma relies heavily on statistics and data analysis,
and many... Continue Reading
In April 2017, overbooking of flight seats hit the headlines
when a United Airlines customer was dragged off a flight. A TED
talk by Nina Klietsch gives a good, but simplistic explanation of
why overbooking is so attractive to airlines.
Overbooking is not new to the airlines; these strategies were
officially sanctioned by The American Civil Aeronautics Board in
1965, and since that time complex... Continue Reading
Can you trust your data?
the very first question we need to ask when we perform a
statistical analysis. If the data's no good, it doesn't matter what
statistical methods we employ, nor how much expertise we have in
analyzing data. If we start with bad data, we'll end up with
unreliable results. Garbage in, garbage out, as they
So, can you trust your data? Are you positive?... Continue Reading
We had solar panels fitted on our property in 2011. Last year,
we had a few problems with the equipment. It was shutting down at
various times throughout the day, typically when it was very sunny,
resulting in no electricity being generated.
In summer 2016, I completed a statistical analysis in Minitab to
confirm my suspicions that my solar panels were not working as well
as they did when they were... Continue Reading
All processes have variation, some of which is inherent in the
process, and isn't a reason for concern. But when processes show
unusual variation, it may indicate a change or a "special
cause" that requires your attention.
Control charts are the primary tool quality practitioners use to
detect special cause variation and distinguish it from natural,
inherent process variation. These charts graph... Continue Reading
may not be a situation more perilous than being a character on
Game of Thrones. Warden of the North, Hand of
the King, and apparent protagonist of the entire series? Off with
your head before the end of the first season! Last male heir of a
royal bloodline? Here, have a pot of molten gold poured on your
head! Invited to a wedding? Well, you probably know what happens at
weddings in the show. ... Continue Reading
How many samples do you need to be “95% confident that at least
95%—or even 99%—of your product is good?
The answer depends on the type of response variable you are
categorical or continuous. The type of response will dictate
whether you 'll use:
Attribute Sampling: Determine the sample size
for a categorical response that classifies each unit as Good or Bad
(or, perhaps, In-spec or... Continue Reading
Have you ever had a probability
plot that looks like this?
The probability plot above is based on patient weight (in
pounds) after surgery minus patient weight (again, in pounds)
The red line appears to go through the data, indicating a
good fit to the Normal, but there are clusters of plotting
points at the same measured value. This occurs on a probability
plot when there are many... 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
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countries around the world.