Re: Special Causes Indicators in Red Bead

["Dr. W. J. Latzko" <Latzko@att.net>]

Dear Mr. Coens,

In the many times that I did the bead experiment, I got two (less than 
0.5%) special cause indications. I suspect that in both cases, the 
"willing" workers did a little manipulating of the process.  I am not as 
strict a foreman as Ed was.

It is always possible for a special cause indication to appear. It does not 
mean that a special cause was really present. It is always important to 
know that there was a special cause in fact before acting as though there 
was one. One has to keep in mind that we often look for a special cause 
when it exists but can't find it.

The only time that I was aware of a special cause in the way Dr. Deming did 
the experiment was when he caught a willing worker cheating and fired him. 
Ed knew what the control limits should be and so could be on the look out 
for deviations. In my case, I have caught the workers trying to bribe the 
inspectors and also had some inefficient inspectors. All of these are 
special causes.

Bill Latzko