When performing a design of experiments (DOE), some factor
levels may be very difficult to change—for example, temperature
changes for a furnace. Under these circumstances, completely
randomizing the order in which tests are run becomes almost
impossible.To minimize the number of factor level changes for a
Hard-to-Change (HTC) factor, a
split-plot design is required.
Why Do We Want to Randomize a... Continue Reading
Design of Experiments is an extremely
powerful statistical method, we added a DOE tool to the Assistant
in Minitab 17 to make it more accessible to more
Since it's summer here, 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 you want to... 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
I've never understood the fascination with selfies.
Maybe it's because I'm over 50. After surviving the slings and
arrows of a half a century on Earth, the minute or two I spend in
front of the bathroom mirror each morning is more than
enough selfie time for me.
Still, when I heard that Microsoft had an online app that estimates
the age of any face on a photo, I was intrigued.
How would the app... Continue Reading
my previous post, I wrote about the hypothesis testing ban in
the Journal of Basic and Applied Social Psychology. I
showed how P values and confidence intervals provide important
information that descriptive statistics alone don’t provide. In
this post, I'll cover the editors’ concerns about hypothesis
testing and how to avoid the problems they describe.
The editors describe hypothesis testing... Continue Reading
This week I'm at the American Society for Quality's World
Conference on Quality and Improvement in Nashville, TN. The ASQ
conference is a great opportunity to see how quality professionals
are tackling problems in every industry, from beverage distribution
to banking services.
Given my statistical bent, I like to see how companies apply
tools like ANOVA, regression, and especially... Continue Reading
As a Minitab
trainer, one of the most common questions I get from training
participants is "what should I do when my data isn’t normal?" A
large number of statistical tests are based on the assumption of
normality, so not having data that is normally distributed
typically instills a lot of fear.
Many practitioners suggest that if your data are not normal, you
should do a nonparametric version of... Continue Reading
2016 presidential race is becoming more real. We’ve had several
announcements with Ted Cruz, Rand Paul, Hillary Clinton, and Marco
Rubio officially entering the race to be President. While the
prospective Democratic candidates are down to one, or at most a
few, the Republican field is extra-large this election cycle. The
first order of business for a GOP candidate is to survive the
nomination... Continue Reading
As a member of Minitab's Technical Support team, I get the
opportunity to work with many people using DOE (Design of
People often will call after they've already chosen their
design, run the experiment, and
identified the important factors in their process. But
now what? They have to find the best settings, but with
several factors and responses, what should they do?
"I wish I had
a... Continue Reading
Imagine that you are watching a race and that you are located
close to the finish line. When the first and fastest runners
complete the race, the differences in times between them will
probably be quite small.
Now wait until the last runners arrive and consider their
finishing times. For these slowest runners, the differences in
completion times will be extremely large. This is due to the fact
that... Continue Reading
Suppose that you have designed a brand new product with many
improved features that well help create a much better customer
experience. Now you must ensure that it is manufactured
according to the best quality and reliability standards, so that it
gets the excellent long-term reputation it deserves from potential
customers. You need to move quickly and seamlessly from Research
and Development into... Continue Reading
now I’m enjoying my daily dose of morning joe. As the steam rises
off the cup, the dark rich liquid triggers a powerful enzyme
cascade that jump-starts my brain and central nervous system,
delivering potent glints of perspicacity into the dark crevices of
my still-dormant consciousness.
Feels good, yeah! But is it good for me? Let’s see what the
Drinking more than 4 cups of coffee... Continue Reading
As someone who has
collected and analyzed real data for a living, the idea of
using simulated data for a Monte Carlo simulation sounds a bit odd.
How can you improve a real product with simulated data? In this
post, I’ll help you understand the methods behind Monte Carlo
simulation and walk you through a simulation example using
What is Devize, you ask? Devize is Minitab's
exciting new,... Continue Reading
You may have been in a situation where you had created a general
full factorial design and noticed that your design’s run size was
higher than you imagined. (Quick refresher: a general full
factorial design is an experimental design where any factor can
have more than 2 levels).
Determined to minimize the monstrous size of your worksheet, you
go back to Stat > DOE > Factorial > Create
Factorial... Continue Reading
I really can’t make this stuff up.
I wrote a post a couple of years ago entitled: “How
to Talk to Your Kids about Six Sigma and Quality
Improvement,” in which I lamented about “Community Hero”
day in my daughter’s 1st grade class and the need to
explain to her why I wasn’t at the "community-hero-level" of
Maggie’s Mommy, the pediatrician.
Well, now it's two years later and my son, Thomas, is in... Continue Reading
Last fall I had a birthday. It wasn’t one of those tougher
birthdays where the number ends in a zero. Still, the birthday got
me thinking. In response, I told myself, age is just a number. Then
I did a mental double-take. Can a statistician say that? After all,
numbers are how I understand the world and the way it works.
Can age just be a number? After some musing, I concluded that
age is just a... Continue Reading
by Jasmin Wong, guest blogger
Part 1 of this two-part blog post discusses the issues and
challenges in injection moulding and suggests using simulation
software and the statistical method called Design of Experiments
(DOE) to speed development and boost quality. This part presents a
case study that illustrates this approach.
Preliminary Fill and Designed Experiment
This case study considers the... Continue Reading
by Jasmin Wong, guest blogger
The combination of statistical methods and injection
moulding simulation software gives manufacturers a
powerful way to predict moulding defects and to
develop a robust moulding process at the part design
CAE (computer-aided engineering) is widely used in the injection
moulding industry today to improve product and mould designs as
well as to resolve or... Continue Reading
statistical techniques to optimize manufacturing processes is
quite common now, but using the same approach on social topics is
still an innovative approach. For example, if our objective is to
improve student academic performances, should we increase teachers
wages or would it be better to reduce the number of students
in a class?
topics (the effect of increasing the minimum... Continue Reading
Screening experimental designs allow you to study a very large
number of factors in a very limited number of runs. The objective
is to focus on the few factors that have a real effect and
eliminate the effects that are not significant. This is often the
initial typical objective of any experimenter when a
DOE (design of experiments) is performed.
Table of Factorial Designs
Consider the table below.... 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.