For each response variable, PROC LATTICE displays
- an "Analysis of Variance" table and related statistics,
including the following as separate sources of variations:
- Blocks within Replications (adjusted for treatments)
- Treatments (unadjusted)
- Intra Block Error
- Randomized Complete Block Error
The Blocks within Replications sum of squares is
further broken down into "Component A" and "Component B."
If there is no repetition of the basic plan, the Component B
sum of squares is the same as the Blocks within Replications
sum of squares. If there is repetition of the basic plan,
the Component A sum of squares reflects the variation
among blocks that contain the same treatments.
The source of variation called Randomized Complete Block
Error is the sum of the Blocks within Replications
sum of squares and the Intra Block Error sum of squares.
It is the appropriate error term if the experimental design
is a randomized complete block design, with the replications
filling the roles of complete blocks.
- two values for the Variance of Means. For some lattice
designs, these are only approximations. The first value is
applicable when the two treatments appear in the same block;
the other (when it appears) applies when the two treatments
never appear in the same block (a possibility in partially
balanced and rectangular designs).
- an Average of Variance. Except with small
designs, it is sufficient to use this average variance of means
for tests between treatments (whether the two treatments
appear in the same block or not); refer to Cochran and Cox (1957).
- the Least Significant Differences (LSDs) at the .01
and .05 levels of significance, based on the Average
- Efficiency Relative to RCBD, the efficiency of the
lattice design relative to a randomized complete block
design. The efficiency is the ratio of the randomized
complete block mean squared error to the effective
error variance; refer to Cochran and Cox (1957).
- the Adjusted Treatment Means. These are adjusted
for blocks if the relative precision is greater than 105
When you specify the COVARIANCE option, PROC LATTICE
produces Sums of
Products and the Mean Product for each
source of variation in the analysis of variance table.
Copyright © 1999 by SAS Institute Inc., Cary, NC, USA. All rights reserved.