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Blind Wine Part IV: The Participants

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 at the number correct by how much each participant usually spends:

Again, no evidence of a relationship (p = 0.559).  

How about how many types each regularly buys?

There appears to be something here,...

Blind Wine Part III: The Results

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 as "A," "B," "C," and "D." 

As Danielle and Sheryl proceed through each tasting, it is easy to note that they start off correctly identifying the color of each wine; it is also obvious that tasting...

Pareto Charts Show Which Data Breach Incidents are Most Common

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 Pareto charts, it was fun for me to come across Verizon Enterprise’s 2014 Data Breach Investigations Report. While the subject probably sounds dry, especially if you don’t know what a data breach is, the...

Blind Wine Part II: The Survey

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 gifts)?
  • Out of the following 8 wines, which do you think you could correctly identify by taste?
  • Merlot
  • Cabernet Sauvignon
  • Pinot Noir
  • Malbec
  • Chardonnay
  • Pinot Grigio
  • Sauvignon Blanc
  • Riesling

Today, we'd like to...

Blind Wine Part I: The Experiment

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 and plum flavors, with some notes of vanilla and leather.

The wine is poured and as Brutus swirls it in his glass and breathes in the aromas, he picks up some of the oak infused into the wine as it aged...

Where Did All the World Cup Goals Go? Find Out with a 2-Sample Poisson Rate Test

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 per game fell off and ended up being pretty similar to other recent World Cups.

What happened?

Comparing the Group Stage to the Knockout Stage

After 15 straight days of games in the group stage, there...

Two-Way ANOVA in Minitab 17

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 new version?  Shouldn’t the new version have more features instead of less? 

Two-Way ANOVA was removed from Minitab 17 because you can get the same output by using the General Linear Model option in...

Guest Post: Did Ma's Diabetes Get Cured by Back Surgery?

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 readings in Minitab Statistical Software.

I did it three times a day before meals...over weeks, then months, then years. At each doctor's appointment I would take in her 'book' of readings, and I would...

Some Stats on the American Statistical Association’s Membership in its 175th Year

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 demographics of ASA membership during its 175th anniversary year. You can read the full post here.

I thought it’d be fun to show off this demographic data using Pie Charts in Minitab 17. I don’t know...

How to Use Brushing to Investigate Outliers on a Graph

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 than sharpening your Minitab skills with real data. Each time the OECD releases their data, we hear about how much money is spent per person on health care compared to how long people live in that...

Bar Chart: Where to Start?

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 are surprised at how many different options are presented when you go to Graph > Bar Chart... in Minitab. There are, in fact, 14 different options based on 1) what you want your final graph to...

A Little Trash Talk: Improving Recycling Processes at Rose-Hulman

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 thrown in the normal trash cans in all of the institution's academic buildings, including the library. Unfortunately, the recycling bins Rose-Hulman has placed all over its campus are underused, and it’s...

Can I Just Delete Some Values to Reduce the Standard Variation in My ANOVA?

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 deviation is low?

In other words, this person wanted a way to automatically eliminate certain values to lower the standard deviation.

Fortunately, Minitab 17 does not have the functionality that this person was...

What Is the Difference between Linear and Nonlinear Equations in Regression Analysis?

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 is the difference between a linear and nonlinear regression equation?

Linear Regression Equations

Linear regression requires a linear model. No surprise, right? But what does that really mean?

A model is linear...

3 Things Baseball Can Teach Us About Control Charts

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 mentioned before that I’m a baseball fan. For the past several years, I’ve been noticing articles about the Year of the Pitcher in Major League Baseball (2010, 2011, 2012, 2013, 2014). That repetition...

Statistics: No Laughing Matter

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 in statistics, and I don't think they make the jokes just because there are so many great statistics-related jokes available. There might be some good jokes about statistics, but I only know two and can only...

You Get a Goal! And You Get a Goal! And You Get a Goal! It’s the 2014 FIFA World Cup!

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 simply attribute it to random variation? Let’s use a data analysis to find out!

Determining a Trend

I went to FIFA’s website and collected the goals per game in every world cup. Now that we have the...

Using Probability Plots to Understand Laser Games Scores

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 is transformed into a linear plot. To do this, the cumulative density function (the so-called CDF, cumulating all probabilities below a given threshold) is used (see the graph below). For a normal...

More "Hidden Helpers" in Minitab Statistical Software

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 Session Window output, graphs, worksheets, command language, and related project areas. You can also copy any or all analyses and graphs to Minitab’s built-in ReportPad to create reports and share your...

Guest Post: Analysis of Road Accidents in Hyderabad

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 obtained from the official website of Hyderabad Traffic Police (http://www.htp.gov.in/Default.htm). Also note that the data for 2014 covers only the period until April.

Reviewing the time series plot I...