Category Archives: Metrics

Six Sigma & The Law of The Hammer

The Bell Curve showing 3 standard deviations

Bell Curve showing Mean, μ & Standard Deviation, σ.

“The child who receives a hammer for Christmas will discover that everything needs pounding.”

One of my friends asked about “Six Sigma,” famously used by General Electric and Motorola to enhance the quality on their production lines, and famously used by Home Depot and 3M for short term gain and long term failure, (see “Six Sigma, So Yesterday,” on Business Week OnLine, here).

“I understand that Six Sigma means a very high quality system – with only 3.4 errors per million units,” my friend said. “What I don’t understand,” he added, “is the definition in terms of Standard Deviation and Normal Distribution. 99.99966% of the values will fall within 6 Standard Deviations of the Mean, compared to 99.73% of the values falling within 3 Standard Deviations of the Mean. What’s a standard deviation? And what’s a normal distribution?” Continue reading

MakeZine.com: “civilian-friendly” Geiger counter

Laura Cochrane, writing on Makezine.com, reports on the development of  A Stylish and More User-Friendly Geiger Counter:

Coming on the heels of the year anniversary of the Japanese Tohoku-Oki earthquake, Bunnie Huang, a member of the MAKE Tech Advisory Board, tasked himself with designing a civilian-friendly Geiger counter. He was inspired by the efforts of Safecast, an organization whose goal is to build an open sensor network that aggregates trustable, source-neutral radiation monitoring data.

The problem with the current crop of radiation monitors is that they are basically laboratory instruments: accurate & reliable, but bulky, expensive, and difficult to use, requiring a degree in nuclear physics to understand exactly what the readings meant. Another problem with crises like these is that while radiation monitoring is important, it’s something that is typically neglected by the civilian population until it is too late.

Therefore, the challenge set out before me was to design a new Geiger counter that was not only more intuitive and easier to use than the current crop, but was also sufficiently stylish so that civilians would feel natural carrying it around on a daily basis.

We need one of these on every block, and lots of radiation detectors with IP addresses, widely dispersed. Because we need that many, essentially in a distributed network, we should be able to manage large economies of scale, with substantial reductions in  price.