When you are analyzing a balanced one-way or two-way design, then if you specify the CL option with METHOD=TYPE1 or GRR, the VARCOMP procedure will compute confidence limits by using modified large-sample (MLS) methods, as discussed in Burdick, Borror, and Montgomery (2005).

The formulas for these confidence limits are very complicated. Those for a balanced two-way crossed random model with interaction are given in Table 94.5. Refer to Burdick, Borror, and Montgomery (2005) for the formulas for one-way or balanced two-way with no interaction models.

Note that confidence limits for parameters such as variances and their ratios might not contain the corresponding point estimates, since negative confidence bounds are increased to zero.

Table 94.5 100()% MLS Confidence Limits

Parameter	Lower Bound	Upper Bound

The terms in Table 94.5 are defined as follows:

The symbol represents the percentile of an F distribution with df1 and df2 degrees of freedom and area to the left.