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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.

Last time, we went over Bar Charts you could create from Counts of Unique Values. However, sometimes you want to convey more information than just simple counts. For example, you could have a number of parts from different models. The number of occurrences themselves don't offer much value, so you may want a chart displaying the means, sums, or even standard deviations of the different parts.... Continue Reading
In Part I, Part II, and Part III we shared our experiment, the survey results, and the experimental results. To wrap things up, we're going to see if the survey results tied to the experimental results in any meaningful way... First, we look at whether self-identified knowledge correlated to the total number of correct appraisals: We have no evidence of a relationship (p = 0.795).  So we'll look... Continue Reading
In Part I and Part II we learned about the experiment and the survey, respectively. Now we turn our attention to the results... Our first two participants, Danielle and Sheryl, enter the conference room and are given blindfolds as we explain how the experiment will proceed.  As we administer the tasting, the colors of the wine are obvious but we don't know the true types, which have been masked... Continue Reading
Everyone loves a Pareto chart. That is, everyone who knows that Pareto charts are a type of bar chart ordered by bar size to help you to determine which bars comprise the vital few that you care about and which are the trivial many that you don't care about. Pareto charts are a great tool for communicating where the largest gains can be made as you focus your improvement efforts. Since I love... Continue Reading
In Blind Wine Part I, we introduced our experimental setup, which included some survey questions asked ahead of time of each participant. The four questions asked were: On a scale of 1 to 10, how would you rate your knowledge of wine? How much would you typically spend on a bottle of wine in a store? How many different types of wine (merlot, riesling, cabernet, etc.) would you buy regularly (not as... Continue Reading
Already relaxed on his first day in Napa, Brutus and his wife Suzy decide to visit their favorite winery just before lunch to taste their new Cabernet Sauvignon. The owner recognizes them as they walk in the door and immediately seats them on the patio overlooking the vineyard. Two glasses appear, and as the owner tells them about the new Cabernet, Brutus prepares for an onslaught of blackberry... Continue Reading
A few weeks ago I looked at the number of goals that were being scored in the World Cup. At the time there were 2.9 goals per game, which was the highest since 1970. Unfortunately for spectators who enjoyed the higher scoring goals, this did not last. By the end, the average had fallen to 2.7 goals per game, the same amount scored in the 1998 World Cup. After such a high-scoring start, the goals... Continue Reading
After upgrading to the latest and greatest version of our statistical software, Minitab 17, some users have contacted tech support to ask "Wait a minute, where is that Two-Way ANOVA option in Minitab 17?"  The answer is that it’s not there. That’s right! The 2-Way ANOVA option that was available in Minitab 16 and prior versions was removed from Minitab 17.Why would this feature be removed from the... 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! Once my Mom was diagnosed with Diabetes Type II, I began to track her blood sugar... Continue Reading
Did you know that this year the American Statistical Association (ASA) is celebrating its 175th anniversary? That’s a pretty significant birthday! On the ASA’s 175thanniversary webpage, they publish blog posts periodically that cover ASA happenings, such as anniversary events and celebrations, as well as interesting tidbits about the organization. Recently, they published a post covering the... Continue Reading
There’s a lot going on in the world, so you might not have noticed that the Organization for Economic Development (OECD) released their new set of health statistics for member nations. On the OECD website, you can now download the free data series for 2014. (Be aware that “for 2014” means that the organization has a pretty good idea about what happened in 2012.) Of course, there’s nothing more fun... Continue Reading
Whether you’re just learning statistics or you're already using data analysis on the job, there are not many tools more straightforward than a bar chart. Bar charts are effective at getting across their message, and are used in a diverse number of fields, from service quality to pharmaceuticals to manufacturing. However, I’ve noticed recently that a lot of customers looking to create a bar chart... Continue Reading
The Six Sigma students at Rose-Hulman Institute of Technology are at it again! A few months back, we blogged about the Six Sigma project they did to reduce food waste at the on-campus dining center. This time, the students—lead by Dr. Diane Evans, Six Sigma black belt and associate professor of mathematics at Rose-Hulman—are performing a Lean Six Sigma project to reduce the amount of recycling... Continue Reading
We received the following question via social media recently: I am using Minitab 17 for ANOVA. I calculated the mean and standard deviation for these 15 values, but the standard deviation is very high. If I delete some values, I can reduce the standard deviation. Is there an option in Minitab that will automatically indicate values that are out of range and delete them so that the standard... Continue Reading
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