DESIGN Subcommand (MANOVA: Univariate command)

DESIGN specifies the effects that are included in a specific model. DESIGN must be the last subcommand entered for any model.

The cells in a design are defined by all of the possible combinations of levels of the factors in that design. The number of cells equals the product of the number of levels of all the factors. A design is balanced if each cell contains the same number of cases. MANOVA can analyze both balanced and unbalanced designs.

  • Specify a list of terms to be included in the model, separated by spaces or commas.
  • The default design, if the DESIGN subcommand is omitted or is specified by itself, is a full factorial model containing all main effects and all orders of factor-by-factor interaction.
  • If the last subcommand that is specified is not DESIGN, a default full factorial design is estimated.
  • To include a term for the main effect of a factor, enter the name of the factor on the DESIGN subcommand.
  • To include a term for an interaction between factors, use the keyword BY to join the factors that are involved in the interaction.
  • Terms are entered into the model in the order in which you list them on DESIGN. If you have specified SEQUENTIAL on the METHOD subcommand to partition the sums of squares in a hierarchical fashion, this order may affect the significance tests.
  • You can specify other types of terms in the model, as described in the following sections.
  • Multiple DESIGN subcommands are accepted. An analysis of one model is produced for each DESIGN subcommand.

Example

MANOVA Y BY A(1,2) B(1,2) C(1,3)
  /DESIGN
  /DESIGN A, B, C
  /DESIGN A, B, C, A BY B, A BY C.
  • The first DESIGN produces the default full factorial design, with all main effects and interactions for factors A, B, and C.
  • The second DESIGN produces an analysis with main effects only for A, B, and C.
  • The third DESIGN produces an analysis with main effects and the interactions between A and the other two factors. The interaction between B and C is not in the design, nor is the interaction between all three factors.