Significance Limit for Autocorrelation
Significance Limit: The limits for the ACF (and PACF ) at the stated Significance Level, if the true population ACF (or PACF) is zero. ACF (or PACF) exceeding this value should be investigated and assumed non-zero.
![]()
where k is the ordinate of the normal distribution at the stated Significance Level (determined using tables of the Normal distribution found in any statistical quality control textbook) and n is the number of observations included in the analysis.