SPSS® 12.0 Command Syntax Reference

864 MANOVA: Univariate
• If you do not use PARTITION, the number refers to a single degree of freedom associated
with the effect.
• The number refers to an individual level for a factor if that factor follows the keyword
WITHIN or MWITHIN (see the sections on nested effects and pooled effects below).
• A factor has one less degree of freedom than it has levels or values.
Example
MANOVA YIELD BY SEED(1,4) WITH RAINFALL
/PARTITION(SEED)=(2,1)
/DESIGN=SEED(1) SEED(2).
• Factor SEED is subdivided into two partitions, one containing the first two degrees of
freedom and the other the last degree of freedom.
• The two partitions of SEED are treated as independent effects.
Nested Effects: WITHIN Keyword
Use the WITHIN keyword (alias W) to nest the effects of one factor within those of another
factor or an interaction term.
Example
MANOVA YIELD BY SEED(1,4) FERT(1,3) PLOT (1,4)
/DESIGN = FERT WITHIN SEED BY PLOT.
• The three factors in this example are type of seed (SEED), type of fertilizer (FERT), and
location of plots (PLOT).
• The DESIGN subcommand nests the effects of FERT within the interaction term of SEED
by PLOT. The levels of FERT are considered distinct for each combination of levels of
SEED and PLOT.
Simple Effects: WITHIN and MWITHIN Keywords
A factor can be nested within one specific level of another factor by indicating the level in
parentheses. This allows you to estimate simple effects or the effect of one factor within only
one level of another. Simple effects can be obtained for higher-order interactions as well.
Use WITHIN to request simple effects of between-subjects factors.
Example
MANOVA YIELD BY SEED(2,4) FERT(1,3) PLOT (1,4)
/DESIGN = FERT WITHIN SEED (1).
• This example requests the simple effect of FERT within the first level of SEED.
• The number (n) specified after a WITHIN factor refers to the level of that factor. It is the
ordinal position, which is not necessarily the value of that level. In this example, the first
level is associated with value 2.