Parameters | Predictive Modeling | PROC MIXED MODEL Statement Options

The MODEL statement names a single dependent variable and the fixed effects, which determine the X matrix of the mixed model.

• dependent is a single dependent variable,

• <fixed-effects> consists of a variable or combination of variables that have a fixed number of levels. Refer to Specification of Effects for instructions on specifying effects.

• </options> specify model building parameters, tolerances, and statistical computations and output.

ALPHA=number This option requests that a t-type confidence interval be constructed for each of the fixed-effects parameters with confidence level 1-number. The value of number must be between 0 and 1; the default is 0.05. This option requests chi-square tests be performed for all specified effects in addition to the F tests. Type 3 tests are the default; you can produce the Type 1 and Type 2 tests by using the HTYPE= option. This option requests that t-type confidence limits be constructed for each of the fixed-effects parameter estimates. The confidence level is 0.95 by default; this can be changed with the ALPHA= option. This option tunes the sensitivity in forming Type 3 functions. Any element in the estimable function basis with an absolute value less than number is set to 0. The default is 1E-8.

Type specific PROC MIXED MODEL options in the PROC MIXED MODEL Statement Options field.For example, to produce the approximate correlation matrix of the fixed-effects parameter estimates for the dependent variable Disease as affected by gender, type Disease=Sex/CORRB, as shown below:Refer to the SAS PROC MIXED MODEL Statement documentation for more information.