RE: SPC - independent data

["Van Putten, Dirk [ETP/SAN]" <Dvanputten@lodanwest.com>]

Hello DEN:

I do not understand the concept of "autocorrelation". I looked in my
statistics books for  definitions and explanations of this concept. I found
about 10 pages dedicated to "The Autocorrelation Function (acf)",
"autocorrelation of/at lag k" and "autocorrelation of coefficient of lag K'
in Nicholas R. Farnum's "Modern Statistical Control and Improvement".

I tried to understand what it means and the significance by reading my book.
The text, IMHO, was difficult to understand without assistance. Will someone
please give me a brief explanation of the concept "autocorrelation" and how
it helps us understand data and variation?

Thank you, Dirk van Putten
dvanputten@lodanwest.com