In Part 1 of this
blog series, I wrote about how statistical inference uses data
from a sample of individuals to reach conclusions about the whole
population. That’s a very powerful tool, but you must check your
assumptions when you make statistical inferences. Violating any of
these assumptions can result in false positives or false negatives,
thus invalidating your results.
The common data... Continue Reading
No matter how experienced you are at analyzing data,
communicating about your results can be a tremendous challenge. So
it's not surprising that "Effectively Reporting Your Data Analysis"
was one of the best-attended sessions at the inaugural Minitab
Insights Conference last month.
The presenters, Benjamin Turcan and Jennifer Berner of First
Niagara Bank, have a great deal of experience improving...Continue Reading
Every day, thousands of people withdraw extra cash for daily
expenses. Each transaction may be small, but the total amount of
cash dispersed over hundreds or thousands of daily transactions can
be very high. But every bank branch has a fixed cash flow, which
must be set without knowing what each customer will need on a given
day. This creates a challenge for financial entities. Customers
expect... Continue Reading
The ultimate goal of most quality improvement projects is clear:
reducing the number of defects, improving a response, or making a
change that benefits your customers.
We often want to jump right in and start gathering and analyzing
data so we can solve the problems. Checking your measurement
systems first, with methods like attribute agreement analysis or
Gage R&R, may seem like a needless waste... Continue Reading
We’ve got a plethora of case studies showing how businesses from different
industries solve problems and implement solutions with data
analysis. Take a look for ideas about how you can use data analysis
to ensure excellence at your business!
Boston Scientific, one of the world’s leading developers of
medical devices, is just one organization who has shared their
story. A team at their Heredia,... Continue Reading
To assess if a process is stable and in statistical control, you
can use a control
chart. It lets you answer the question "is the process that you
see today going to be similar to the process that you see
tomorrow?" To assess and quantify how well your process falls
within specification limits, you can use capability
Both of these tools are easy to use in Minitab, but you
first need to... Continue Reading
when I used to work in Minitab Tech Support, customers often asked
me, “What’s the difference between Cpk and Ppk?” It’s a good
question, especially since many practitioners default to using Cpk
while overlooking Ppk altogether. It’s like the '80s pop
duo Wham!, where Cpk is George Michael and Ppk is that other
Poofy hairdos styled with mousse, shoulder pads, and leg warmers
aside, let’s... Continue Reading
When I blogged about
automation back in March, I made my husband out to be an
automation guru. Well, he certainly is. But what you don’t know
about my husband is that while he loves to automate everything in
his life, sometimes he drops the ball. He’s human; even I have to
cut him a break every now and then.
On the other hand, instances of hypocrisy in his behavior tend
to make for a good story.... Continue Reading
Here is a scenario involving process capability that we’ve seen
from time to time in Minitab's technical support department. I’m
sharing the details in this post so that you’ll know where to look
if you encounter a similar situation.
You need to run a capability analysis. You generate the output
Statistical Software. When you look at the results, the Cpk is
huge and the histogram in... 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
You often hear the data being
blamed when an analysis is not delivering the answers you wanted or
expected. I was recently reminded that the data chosen or collected
for a specific analysis is determined by the analyst, so there is
no such thing as bad data—only bad
This made me think about the
steps an analyst can take to minimise the risk of producing
analysis that fails to answer... Continue Reading
last thing you want to do when you purchase a new piece of software
is spend an excessive amount of time getting up and running. You’ve
probably been ready to the use the software since, well,
yesterday. Minitab has always focused on making our
software easy to use, but many professional software packages do
have a steep learning curve.
Whatever package you’re using, here are three things you... Continue Reading
What does the eyesight of a homeless person have in common with
complications from dental anesthesia? Or with reducing
side-effects from cancer? Or monitoring artificial hip
These are all subjects of recently published studies that
analyses in Minitab to improve healthcare
outcomes. And they're a good reminder that when we
improve the quality of healthcare for others, we... Continue Reading
We often receive questions about moving ranges because they're
used in various tools in our statistical software,
including control charts and capability analysis when data is not
collected in subgroups. In this post, I'll explain what a moving
range is, and how a moving range and average moving range are
A moving range measures how variation changes over time when
data are collected as... Continue Reading
After my husband’s most recent visit to the dentist, he returned
home cavity-free...and with a $150 electric toothbrush in
I wanted details.
It began innocently. His dreaded trip to the dentist ended in
high praise for no cavities and only a warning to floss more. That
prompted my programming-and-automation-obsessed husband, still in
the chair, to exclaim, "I wish there was a way to automate... Continue Reading
the roots of Lean Six Sigma and other quality improvement
methodologies are in manufacturing, it’s interesting to see how
other organizational functions and industries apply LSS tools
successfully. Quality improvement certainly has moved far beyond
the walls of manufacturing plants!
For example, I recently had the opportunity to talk to Drew
Mohler, a Lean Six Sigma black belt and senior... Continue Reading
If you need to assess process
performance relative to some specification limit(s),
capability is the tool to use. You collect some accurate
data from a stable process, enter those measurements in Minitab,
and then choose Stat > Quality Tools >
Capability Analysis/Sixpack or Assistant
> Capability Analysis.
Now, what about sorting the data?
I’ve been asked “why does Cpk change when I... Continue Reading
How deeply has statistical content from Minitab blog posts (or
other sources) seeped into your brain tissue? Rather than submit a
biopsy specimen from your temporal lobe for analysis, take this
short quiz to find out. Each question may have more than one
correct answer. Good luck!
of the following are famous figure skating pairs, and which are
methods for testing whether your data follow a... Continue Reading
Having delivered training courses on
capability analyses with Minitab, several times, I have noticed
that one question you can be absolutely sure will be asked, during
the course, is: What is the difference between the Cpk
and the Ppk indices?
Ppk vs. Cpk indices
The terms Cpk and Ppk are often confused,
so that when quality or process engineers refer to the
Cpk index, they often actually intend to... Continue Reading
Control charts are a fantastic tool. These charts plot your
process data to identify common cause and special cause variation.
By identifying the different causes of variation, you can take
action on your process without over-controlling it.
Assessing the stability of a process can help you determine
whether there is a problem and identify the source of the problem.
Is the mean too high, too low,... Continue Reading
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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.