Every fixed effect that you specify in the model is assigned a certain number of algebraic parameters in the linear model. The number of parameters for each effect is determined by the number of levels of each of the
class variables in the effect. By clicking the
+ and
- buttons, you assign coefficients to these algebraic parameters. For example, by clicking
+ for one treatment level and
- for a control level, you create a difference between these two particular parameters.
All of the coefficients within an effect for which + is clicked are averaged, so the assigned coefficients sum to one. In this way you can construct differences of averages. For estimates of differences, the intercept coefficient should be left at 0. You can also construct estimates of
means, for which the intercept coefficient is typically 1. The scientific
null hypothesis tested is that the sum of all nonzero coefficients times their corresponding algebraic parameters equals zero.
When the coefficients in the boxes are as you desire, click Create an Estimate Statement Below to construct a single SAS
ESTIMATE statement in the text box. Click
Clear Entries Above to reset all coefficients to zero in order to start building another Estimate statement. You can also delete or edit the statements directly in the text box. In this way you can construct an arbitrary number of simple or complex
hypothesis tests.
When finished, click Save Estimate Statements to Output File in order to save all of the statements to the output file. This file can then be used as input in the
ANOVA or
Mixed Model Analysis analytical processes. Make sure the
Class Variables and
Fixed Effects are specified in exactly the same order in both the
Estimate Builder initial dialog and in
ANOVA or
Mixed Model Analysis, otherwise the order of the coefficients can be incorrect.