A reader asked a great
question in response to a post I wrote
about Pareto charts. Our readers typically do ask great questions,
but this one turned out to be more difficult to answer than it
My correspondent wrote:
My understanding is that when you have count data, a
bar chart is the way to go. The gaps between the bars emphasize
that the data are not measured on a continuous scale.... Continue Reading
We hosted our first-ever Minitab Insights conference in
September, and if you were among the attendees, you already know
the caliber of the speakers and the value of the information they
shared. Experts from a wide range of industries offered a lot of
great lessons about how they use data analysis to improve business
practices and solve a variety of problems.
I blogged earlier about five key...Continue Reading
watched an old motorcycle flick from the 1960s the other night, and I
was struck by the bikers' slang. They had a language all their own.
Just like statisticians, whose manner of speaking often confounds
those who aren't hep to the lingo of data analysis.
It got me thinking...what if there were an all-statistician
biker gang? Call them the Nulls Angels. Imagine them in their
colors, tearing... Continue Reading
If you were among the 300 people who attended the first-ever
Minitab Insights conference in September, you already know how
powerful it was. Attendees learned how practitioners from a
wide range of industries use data analysis to address a variety of
problems, find solutions, and improve business practices.
In the coming weeks and months, we will share more of the great
insights and guidance shared... Continue Reading
I confess: I'm not a natural-born decision-maker. Some people—my
wife, for example—can assess even very complex situations, consider
the options, and confidently choose a way forward. Me? I get
anxious about deciding what to eat for lunch. So you can imagine
what it used to be like when I
needed to confront a really big decision or problem. My approach,
to paraphrase the Byrds, was "Re:... Continue Reading
other day I was talking with a friend about control charts, and I
wanted to share an example one of my colleagues wrote on the
Minitab Blog. Looking back through the index for "control
charts" reminded me just how much material we've published on this
Whether you're just getting started with control charts, or
you're an old hand at statistical process control, you'll find some
valuable... Continue Reading
So the data you nurtured, that you worked so hard to format and
make useful, failed the normality test.
Time to face the truth: despite your best efforts, that data set
is never going to measure up to the assumption you may
have been trained to fervently look for.
Your data's lack of normality seems to make it poorly suited for
analysis. Now what?
Take it easy. Don't get uptight. Just let your data... Continue Reading
Figures lie, so they say, and liars figure. A recent post at Ben
Orlin's always-amusing mathwithbaddrawings.com blog nicely
encapsulates why so many people feel wary about anything
related to statistics and data analysis. Do take a moment to check it out, it's a fast
all of the scenarios Orlin offers in his post, the statistical
statements are completely accurate, but the person offering... Continue Reading
You need to consider many factors when you’re buying a used car.
Once you narrow your choice down to a particular car model, you can
get a wealth of information about individual cars on the market
through the Internet. How do you navigate through it all to find
the best deal? By analyzing the data you have available.
Let's look at how this works using
the Assistant in Minitab 17. With the... Continue Reading
Design of Experiments is an extremely
powerful statistical method, and we added a DOE tool to the
Assistant in Minitab 17 to make it more accessible to more
Since it's summer grilling season, I'm
applying the Assistant's DOE tool to outdoor
cooking. Earlier, I showed
to set up a designed experiment that will let you optimize how
you grill steaks.
If you're not already using it and... Continue Reading
Design of Experiments (DOE) has a reputation for difficulty, and
to an extent, this statistical method deserves that
reputation. While it's easy to grasp the basic idea—acquire the
maximum amount of information from the fewest number of
experimental runs—practical application of this tool can
quickly become very confusing.
if you're a long-time user of designed experiments, it's still easy
to... Continue Reading
Earlier this month, PLOS.org
published an article titled "Ten Simple Rules for Effective Statistical
10 rules are good reading for anyone who draws conclusions and makes decisions
based on data, whether
you're trying to extend the boundaries of scientific knowledge or
make good decisions for your business.
Carnegie Mellon University's
Robert E. Kass and several co-authors devised... Continue Reading
By looking at the data we have about 500 cardiac patients, we've
learned that easy access to the hospital and good transportation
are key factors influencing participation in a rehabilitation
data shows that each month, about 15 of the patients discharged
after cardiac surgery do not have a car. Providing transportation
to the hospital might make these patients more likely to join... Continue Reading
In part 2 of this series, we used graphs and tables to see
how individual factors affected rates of patient participation
in a cardiac rehabilitation program. This initial look at the data
indicated that ease of access to the hospital was a very important
contributor to patient participation.
this revelation, a bus or shuttle service for people who do not
have cars might be a good way to... Continue Reading
Over the past year I've been able to work with and learn from
practitioners and experts who are using data analysis and Six Sigma
to improve the quality of healthcare, both in terms of operational
efficiency and better patient outcomes. I've been struck by how
frequently a very basic analysis can lead to remarkable
improvements, but some insights cannot be attained without
conducting more... Continue Reading
There has been plenty of noisy disagreement about the state of
health care in the past several years, but when you get beyond the
controversies surrounding various programs and changes, a great
deal of common ground exists.
agrees that there's a lot of waste and inefficiency in the way
we've been doing things, and that health care should be delivered
as efficiently and effectively as... Continue Reading
If you want to convince someone that at least a basic
understanding of statistics is an essential life skill, bring up
the case of Lucia de Berk. Hers is a story that's too awful to be
true—except that it is completely true.
flawed analysis irrevocably altered de Berk's life and kept her
behind bars for five years, and the fact that this analysis
targeted and harmed just one person makes it more... Continue Reading
In an earlier post, I shared an
overview of acceptance sampling, a method that lets you
evaluate a sample of items from a larger batch of products (for
instance, electronics components you've sourced from a new
supplier) and use that sample to decide whether or not you should
accept or reject the entire shipment.
There are two approaches to acceptance sampling. If you do it by
attributes, you... Continue Reading
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