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Statistics Online

Blog posts and articles that offer tips about statistics and analyzing data for quality improvement.

A few weeks ago my colleague Cody Steele illustrated how the same set of data can appear to support two contradictory positions. He showed how changing the scale of a graph that displays mean and median household income over time drastically alters the way it can be interpreted, even though there's no change in the data being presented. When we analyze data, we need to present the results in... 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
"He looks just like his father...and mother!" Popular morphing sites online let you visualize the hypothetical offspring of some very unlikely couples. The baby of Albert Einstein and Kim Kardashian (Kimbert?) would presumably look something like the image shown at right. What happens if you morph the features of two different graphs? For example, what would the baby of a time series plot and... Continue Reading
The 2014-15 NFL season is only days away, and fans all over the country are planning their fall weekends accordingly. In this post, I'm going to use data analysis to answer some questions related to ticket prices, such as: Which team is the least/most expensive to watch at home?  Which team is the least/most expensive to watch on the road?  If you are thinking of a road trip, which stadiums offer... Continue Reading
I caught the end of Toy Story over the weekend, which is definitely one of my all-time favorite children’s movies. Now—unfortunately or fortunately—I can’t get Randy Newman's theme song,“You’ve Got a Friend in Me,” out of my head! It's also got me thinking about the nature of friendship, and how "best friends forever" are supposed to always be there when you need them. And, not to get too maudlin... 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
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
These days, my memory isn't what it used to be. Besides that, my memory isn't what it used to be.  But my incurable case of CRS (Can't Remember Stuff) is not nearly as bad as that of the exponential distribution. When modelling failure data for reliability analysis, the exponential distribution is completely memoryless. It retains no record of the previous failure of an item. That might sound like a... Continue Reading
A colleague of mine at Minitab, Cheryl Pammer, was recently featured in "A Statistician's Journey," a monthly feature that appears in the print and online versions of the American Statistical Association's AMSTAT News magazine.   Each month, the magazine asks ASA members to talk about the paths they took to get to where they are today. Cheryl is a "user experience designer" at Minitab. In other... Continue Reading
Two weeks ago Penn State and Michigan played in a quadruple-overtime thriller that almost went into a 5th overtime. Had Penn State coach Bill O’Brien kicked a field goal in the 4th overtime instead of going for it on 4th and 1, the game would have continued. But the Nittany Lions converted the 4th down (which, by the way, wasn’t a gamble) and went on to score the game winning touchdown in the 4th... Continue Reading
In my home, we’re huge fans of Mythbusters, the show on Discovery Channel. This fun show mixes science and experiments to prove or disprove various myths, urban legends, and popular beliefs. It’s a great show because it brings the scientific method to life. I’ve written about Mythbusters before to show how, without proper statistical analysis, it’s difficult to know when a result is statistically... Continue Reading
Failure to properly calibrate this machine will result in defective rock and roll.  In my last post, I imagined using the example of a rock and roll band -- the Zero Sigmas -- to explain Pareto charts to my music-loving but statistically-challenged boss. I showed him how easy it was to use a Pareto chart to visualize defects or problems that occur most often, using the example of various incidents... Continue Reading
We usually think of games as a distraction—just something we do for fun. However, growing evidence suggests that games can do much more, especially when it comes to learning in a classroom setting. Because statistics is a topic that doesn’t come easily to most, using properly designed games to teach statistics can become a valuable tool to spark interest and help explain difficult concepts. So what... Continue Reading
Data.  Analysis. Statistics. It seems like everybody is talking about the importance of doing data analysis, whether it's analytics for predicting consumer behavior or looking at critical metrics for Six Sigma and other data-driven quality improvement programs. Not only do we have more data available to us than ever before, we're also blessed...and/or cursed...with an enormous range of software... Continue Reading
If the title of this post made you think you’d be reading about Abraham Lincoln and Tyra Banks, you’re only half right.  A few weeks ago, statistician and journalist Nate Silver published an interesting post  on how U.S. presidents are ranked by historians. Silver showed that the percentage of electoral votes that a U.S. president receives in his 2nd term election serves as a rough predictor of... Continue Reading
One of the most poorly understood concepts in the use of statistics is the idea of assumptions. You've probably encountered many of these assumptions, such as "data normality is an assumption of the 1-sample t-test."  But if you read that statement and believe normality is a requirement of the 1-sample t-test, then you have missed a subtle and important characteristic of assumptions and need to... Continue Reading
Want to learn more about analyzing data? Try taking a page from Aesop's book.  Well...really, I'm suggesting taking multiple pages from Minitab's book, but my suggestion stems from an idea that Aesop epitomizes.   Aesop was no fool. When he wanted to convey even the heaviest of lessons, he didn't waste time detailing the intellectual and philosophical arguments behind them. He didn't argue, cajole,... Continue Reading
Have you shopped online to buy gifts this holiday season? With Cyber Monday (the Monday following Black Friday) offering shoppers free shipping and other great discounts for buying online, it’s hard not to take advantage of virtual deals. I find myself purchasing more and more of my Christmas list online every year, and after comScore’s recent release of this year’s online holiday spending... Continue Reading
Traditionally, the pieces and parts for most anything we buy are designed and manufactured one-by-one and then assembled into the final product we see on store shelves.  Everything from cars and jet engines to sneakers and cell phones are produced this way.  With the advent of additive manufacturing or “3D printing,” that familiar formula may soon change.  In this process, a virtual design is fed... Continue Reading