Counterpoint, Rip?

[Thomas Phillip Ryan <tpryan@umich.edu>]

> Hope this hasn't muddied the waters too much...I'm sure 
> Tom Ryan will jump in with a counterpoint :--)

I don't really have any problem with the content of the
full message, but I do have problems with the content of
other recent messages regarding control charts and
non-normality.

The bottom line is that non-normality is *potentially*
a serious problem, especially when individual observations
are plotted. This is easy to demonstrate, and has
been demonstrated in various papers.

Undoubtedly many of you will disagree, but I suggest
that you at least read my comments on this matter that
will appear soon in the October issue of the Journal of
Quality Technology.

Tom Ryan
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