Talk:Common cause and special cause (statistics)

Walter Shewhart
In paragraph What does the bold paragraph mean, it is missing something. -- SGBailey 12:59, 2005 Jun 9 (UTC)
 * "Walter A. Shewhart originally used the term chance-cause. The term common-cause was coined by Harry Alpert in 1947. Shewhart called a process that features only common-cause variation in statistical control. This term is deprecated by some modern statisticians who prefer the phrase stable and predictable."
 * The original quotes (italics)?
 * Walter A. Shewhart originally used the term chance-cause. The term common-cause was coined by Harry Alpert in 1947. Shewhart called a process that features only common-cause variation "in statistical control". This term is deprecated by some modern statisticians who prefer the phrase "stable and predictable".
 * Cutler 16:21, Jun 9, 2005 (UTC)

hey,

I think the special cause variation in this article is wrong!!

It is meant to say, that the variation CAN be attributed to a SPECIFIC cause, and is not just random vairation James

A different but important meaning of "common cause"
I read the account in the article, which is clear enough, with some surprise. Two failures have a "common cause" if both are caused by the same thing. When your aircraft flies over a volcano and all the engines go out because volcanic dust has melted all over the combustion chambers and turbine blades, there is no sense in saying this was more improbable than the failure of one engine, because the same events and the same logic apply to each engine. Since this is a different but important usage of the same term, with relevance to statistics, perhaps someone more knowledgeable than me about the field could put some kind of note into the article? (Perhaps with xref to other articles on safety engineering and so on.) Chiswick Chap (talk) 20:16, 9 October 2012 (UTC)

example special v common cause lst
I am not a fan of the list of causes. I don't think it communicates the difference between special and common causes. Without objection I will edit it a little based on some of my textbooks. — Preceding unsigned comment added by 108.208.161.137 (talk) 16:41, 8 January 2013 (UTC)


 * It sounds as if you should go ahead and fix it. Chiswick Chap (talk) 17:29, 8 January 2013 (UTC)