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Tips and Techniques for Statistics and Quality Improvement

Blog posts and articles about using Minitab software in quality improvement projects, research, and more.

Previously, I’ve written about when to choose nonlinear regression and how to model curvature with both linear and nonlinear regression. Since then, I’ve received several comments expressing confusion about what differentiates nonlinear equations from linear equations. This confusion is understandable because both types can model curves. So, if it’s not the ability to model a curve, what isthe... Continue Reading
Control charts are some of the most useful tools in statistical science. They track process statistics over time and detect when the mean or standard deviation change from what they have been. The signals that control charts send about special causes can help you zero in on the fastest ways to improve any process, whether you’re making tires, turbines, or trying to improve patient care. I’ve menti... Continue Reading
by Matthew Barsalou, guest blogger  I told a friend about my interest in statistics, and he immediately told me a joke about broiled chicken and statistics. The punch line involved my friend getting to eat all the chicken. Unfortunately, I forgot the rest of the joke. I can, however, assure you it was a very funny statistics-related joke. People often make jokes when I mention my interest... Continue Reading
The 2014 World Cup has gotten off to a high-scoring start. Through the first week of the tournament, an average of 2.9 goals have been scored per game, the highest since 1970. And if that average climbs to over 3 goals per game, this’ll be the highest scoring World Cup since 1958! So is this year’s World Cup actually bucking a trend of the low scoring tournaments that came before it, or can we... Continue Reading
There is more than just the p value in a probability plot—the overall graphical pattern also provides a great deal of useful information. Probability plots are a powerful tool to better understand your data. In this post, I intend to present the main principles of probability plots and focus on their visual interpretation using some real data. In probability plots, the data density distribution... Continue Reading
In an earlier post, I shared some great hidden helpers in Minitab Statistical Software that even many veteran users don't know about. Here are a few more! Everything In Its Right Place Minitab’s Project Manager allows you to navigate, view, and manipulate various parts of your project. Right-clicking either the folders or their contents lets you access a variety of menus that allow you to manage... Continue Reading
The Minitab Fan section of the Minitab blog is your chance to share with our readers! We always love to hear how you are using Minitab products for quality improvement projects, Lean Six Sigma initiatives, research and data analysis, and more. If our software has helped you, please share your Minitab story, too!   An Analysis of Road Accidents in Hyderabad, India The data taken for this study is... Continue Reading
In regression analysis, you'd like your regression model to have significant variables and to produce a high R-squared value. This low P value / high R2 combination indicates that changes in the predictors are related to changes in the response variable and that your model explains a lot of the response variability. This combination seems to go together naturally. But what if your regression model... Continue Reading
Toolbars are there to make your life easier, but if you don’t take the time to hover over each button and wait for a description, it’s pretty easy to never know that there’s a faster way to do something. The toolbars in Minitab Statistical Software include some pretty nifty shortcuts. Here are my favorite 6: StatGuide As soon as you have results in Minitab, the StatGuide button becomes active on... Continue Reading
You know what really gets on my nerves? A lot of things. That slow, slinky way that cats walk by. Grrrr. The rude, abrupt arrival of delivery persons in their obnoxiously loud trucks. (Why do they always pull up just as I’m settling down for a nap?) Grrrr. Total strangers who reach down and poke me with fat, clumsy fingers that reek of antibacterial soap. Grrrr. And this one always gets my dander up:... Continue Reading
A recent study has indicated that female-named hurricanes kill more people than male hurricanes. Of course, the title of that article (and other articles like it) is a bit misleading. The study found a significant interaction between the damage caused by the storm and the perceived masculinity or femininity of the hurricane names. So don’t be confused by stories that suggest all... Continue Reading
Remember "The Little Engine That Could," the children's story about self-confidence in the face of huge challenges? In it, a train engine keeps telling itself "I think I can" while carrying a very heavy load up a big mountain. Next thing you know, the little engine has done it...but until that moment, the outcome was uncertain. It's a wonderful story for teaching kids about self-confidence. But... Continue Reading
by Matthew Barsalou, guest blogger Programs such as the Minitab Statistical Software make hypothesis testing easier; but no program can think for the experimenter. Anybody performing a statistical hypothesis test must understand what p values mean in regards to their statistical results as well as potential limitations of statistical hypothesis testing. A p value of 0.05 is frequently used during... Continue Reading
From 1985 until 2013, the NBA Finals used a 2-3-2 format to decide the NBA Champion. That is, the first 2 games are played at one team’s arena, followed by 3 in a row at the other team’s, then the last two at the first team’s. However, this year they are changing to the 2-2-1-1-1 format, where each team plays 2 of the first four games at home, then they alternate each game for games 5-7. So how... Continue Reading
In Minitab, the Assistant menu is your interactive guide to choosing the right tool, analyzing data correctly, and interpreting the results. If you’re feeling a bit rusty with choosing and using a particular analysis, the Assistant is your friend! Previously, I’ve written about the new linear model features in Minitab 17. In this post, I’ll work through a multiple regression analysis example and... Continue Reading
Minitab graphs are powerful tools for investigating your process further and removing any doubt about the steps you should take to improve it. With that in mind, you’ll want to know every feature about Minitab graphs that can help you share and communicate your results effectively. While many ways to modify your graph are on the Editor menu, some of the best features become available when you... Continue Reading
Minitab Statistical Software offers many features that can save you time and effort when you’re learning statistics or analyzing data. However, when we demonstrate many of these short cuts, tools, and capabilities at shows and events, we find that even some longtime users aren’t aware of them. I asked members of our sales team and technical support staff to list some of Minitab’s most helpful, yet... Continue Reading
It's all too easy to make mistakes involving statistics. Powerful statistical software can remove a lot of the difficulty surrounding statistical calculation, reducing the risk of mathematical errors—but  correctly interpreting the results of an analysis can be even more challenging.  No one knows that better than Minitab's technical trainers. All of our trainers are seasoned statisticians with... Continue Reading
Many of my close friends and family members are nurses, and I’ve noticed (via Facebook of course) that many recently celebrated National Nurses’ Week, which ran Tuesday, May 6 through Monday, May 12—the actual birthday of Florence Nightingale. Florence Nightingale is known as the founder of modern nursing, but you might not know that she is also a celebrated statistician. When I started reading... Continue Reading
We cannot improve what we cannot measure. Therefore, it is critical that we conduct a measurement systems analysis (MSA) before we start analyzing our data to make any kind of decisions. When conducting an MSA for continuous measurements, we typically using a Gage R&R Study. And in these Gage R&R Studies, we look at output such as the percentage study variation (%Study Var, or %SV) and the Number... Continue Reading