Specifying How Data Were Recorded
You must specify the way in which preference data were recorded.
Data can be recorded in one of three ways: sequentially, as rankings,
or as preference scores. These three methods are indicated by the SEQUENCE, RANK, and SCORE subcommands. You
must specify one, and only one, of these subcommands as part of a CONJOINT command.
SEQUENCE Subcommand
The SEQUENCE subcommand indicates
that data were recorded sequentially so that each data point in the
data file is a profile number, starting with the most preferred profile
and ending with the least preferred profile. This is how data are
recorded if the subject is asked to order the profiles from the most
to the least preferred. The researcher records which profile number
was first, which profile number was second, and so on.
CONJOINT PLAN=* /DATA='RUGRANKS.SAV'
/SEQUENCE=PREF1 TO PREF22.- The variable PREF1 contains the profile number for the most preferred profile out of 22 profiles in the orthogonal plan. The variable PREF22 contains the profile number for the least preferred profile in the plan.
RANK Subcommand
The RANK subcommand indicates
that each data point is a ranking, starting with the ranking of profile
1, then the ranking of profile 2, and so on. This is how the data
are recorded if the subject is asked to assign a rank to each profile,
ranging from 1 to n, where n is the number of profiles. A lower rank
implies greater preference.
CONJOINT PLAN=* /DATA='RUGRANKS.SAV'
/RANK=RANK1 TO RANK22.- The variable RANK1 contains the ranking of profile 1, out of a total of 22 profiles in the orthogonal plan. The variable RANK22 contains the ranking of profile 22.
SCORE Subcommand
The SCORE subcommand indicates
that each data point is a preference score assigned to the profiles,
starting with the score of profile 1, then the score of profile 2,
and so on. This type of data might be generated, for example, by asking
subjects to assign a number from 1 to 100 to show how much they liked
the profile. A higher score implies greater preference.
CONJOINT PLAN=* /DATA='RUGRANKS.SAV'
/SCORE=SCORE1 TO SCORE22.- The variable SCORE1 contains the score for profile 1, and SCORE22 contains the score for profile 22.