Specify constant numeric values for each variance component in the

model, including the residual variance, in this field.

All power calculations are conditioned on these values. That is, they are assumed to be the true values of the variance components. Larger values correspond to more variability and less power.

Tip: You can determine appropriate values by running the

ANOVA or

Mixed Model Analysis processes on pilot study data. Use a statistic such as the

mean or a

quantile from the empirical

distribution. To obtain these from the

_owa,

_amr, or

_mmr tables, click

Analyze > Distribution and select

variables beginning with

Variance_.