PLAN Subcommand (CONJOINT command)

PLAN identifies the file containing the full-concept profiles.

  • PLAN is followed by quoted file specification for an external IBM® SPSS® Statistics data file or currently open dataset containing the plan. An asterisk instead of a file specification indicates the active dataset.
  • If the PLAN subcommand is omitted, the active dataset is assumed by default. However, you must specify at least one IBM SPSS Statistics data file or dataset on a PLAN or DATA subcommand. The active dataset cannot be specified as both the plan file and data file.
  • The plan file is a specially prepared file that is generated by ORTHOPLAN or entered by the user. The plan file can contain the variables CARD_ and STATUS_, and it must contain the factors of the conjoint study. The value of CARD_ is a profile identification number. The value of STATUS_ is 0, 1, or 2, depending on whether the profile is an experimental profile (0), a holdout profile (1), or a simulation profile (2).
  • The sequence of the profiles in the plan file must match the sequence of values in the data file.
  • Any simulation profiles (STATUS_=2) must follow experimental and holdout profiles in the plan file.
  • All variables in the plan file except CARD_ and STATUS_ are used as factors by CONJOINT.

Example

DATA LIST FREE /CARD_ WARRANTY SEATS PRICE SPEED STATUS_.
BEGIN DATA
1 1 4 14000 130 2
2 1 4 14000 100 2
3 3 4 14000 130 2
4 3 4 14000 100 2
END DATA.
ADD FILES FILE='/DATA/CARPLAN.SAV'/FILE=*.
CONJOINT PLAN=* /DATA='/DATA/CARDATA.SAV'
  /FACTORS=PRICE (ANTIIDEAL) SPEED (LINEAR) WARRANTY (DISCRETE MORE)
  /SUBJECT=SUBJ /RANK=RANK1 TO RANK15 /PRINT=SIMULATION.
  • DATA LIST defines six variables—a CARD_ identification variable, four factors, and a STATUS_ variable.
  • The data between BEGIN DATA and END DATA are four simulation profiles. Each profile contains a CARD_ identification number and the specific combination of factor levels of interest.
  • The variable STATUS_ is equal to 2 for all cases (profiles). CONJOINT interprets profiles with STATUS_ equal to 2 as simulation profiles.
  • The ADD FILES command joins an old plan file, CARPLAN.SAV, with the active dataset. Note that the active dataset is indicated last on the ADD FILES command so that the simulation profiles are appended to the end of CARPLAN.SAV.
  • The PLAN subcommand on CONJOINT defines the new active dataset as the plan file. The DATA subcommand specifies a data file from a previous CONJOINT analysis.