Scatter diagram – how handy is that?

Steve DaumScatter diagrams: a scattered approach? Steve Daum shows how this simple tool establishes support for understanding the correlations (and non-correlations) among factors.

In recent work, I’ve been thinking about the use and application of scatter diagrams. You have probably seen these. Here are some examples:

When you look at a scatter diagram, you are testing a theory. Statisticians call this testing a hypothesis. These scatter diagrams compare two variables: one variable on the horizontal or x-axis and a different variable on the vertical or y-axis. The theory you are testing is that there is no significant correlation between these two variables.

The quick answer to the question Is the theory correct? can be found by looking at the slope of the line. The flatter or more horizontal the line is, the more comfortable you can be that your theory is correct – that is: there is no significant correlation between these two variables. The steeper the slope, either downward or upward, indicates that your hypothesis is not correct. That is there does appear to be correlation between these variables. However, like almost everything with statistics, the quick answer does not tell the whole story.

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Quality quiz (August 2015): A classic quiz from Professor Cleary—and July’s quiz winners!

Mike ClearyWinners of last month’s quiz and a copy of Quality Quiz Classics are Rick Carsten (Leser LLC); Abdul Khatri (Kamet); and Louis McDaniels (Texas A&M University). Congratulations! For this month’s quiz, and a chance to win a copy of Quality Gamebox, submit your response by August 31.

To celebrate the life and work of Professor Cleary, we are featuring a classic quiz from our archives.

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Bytes and pieces: News you can use

ISO update: Management system standard ISO 9001 is in the final revision process. ISO member countries have 2 months to form a national position and vote on the latest draft of the standard before the 9 September deadline.

Service quality: Register now for ASQ’s 24th Annual Service Quality Conference in Orlando, September 28 and 29.

Survey: Contribute to worldwide quality research by participating in this survey.

Quality reading opportunity: Order your copy of The Transformative Workplace: Growing People, Purpose, Prosperity, and Peace by Carole and David Schwinn for interviews with highly successful workplace leaders all over the world.

Improving quality in the supply chain—by talking about it

Barb ClearyWord of mouth may have the greatest influence when it comes to sharing information—both positive and negative– about products and services, most will agree. We think of a neighbor raving about his new lawn mower, or a co-worker sharing a positive experience with a plumbing service. While consumer products come to mind when we talk about word of mouth, the same process applies when it comes to the supply chain that produces these products.

Large automotive manufacturers such as Ford or GM depend on countless purveyors of parts and services that go into the final product, and count on these suppliers to provide quality products to support the final product quality. Certification to standards such as the ISO 9001 requirements are created to assure that this will happen.

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Bytes and pieces: News you can use

Analytics and intelligence: Here are ten business intelligence trends you will want to consider in a changing business environment.

Golf analyzed: Davis Balestracci uses golf statistics to demonstrate how information is gleaned from data.

Quality as competitive edge: In the race for manufacturing success, Dan Slater says, quality is more important than productivity, even as the industry watches man-hours data.

Korean car brands top quality list: A J.D. Power study shows Japanese autos falling behind Kia and Hyundai models.