Importing Utility Runs

Overview

SMRT can automatically import conjoint part-worth data generated by any of Sawtooth Software's current conjoint software systems by clicking Analysis | Run Manager | Import…. (The number of attributes and levels per attribute to be imported cannot exceed the limitations of your system). It can also import part-worths that you have generated in most any other standard way, as long as you format those data as an .HBU file and optionally create a file describing the coded linear terms (.VAL) if they apply.

The formats automatically imported by the Market Simulator are:

HB Utilities (*.hbu, *.hbc)

ACA or ACA v4.x (*.utl)

CVA (Traditional Conjoint) Utilities (*.utl)

Latent Class Utilities (*.pxx)

Generic Conjoint File (*.hbu)

Latent Class, HB Utilities, and the Generic Conjoint *.hbu formats are the most complex, allowing for a great deal of flexibility in the inputs, including first-order interactions and linear term specifications of utilities.

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Importing Utilities into the Market Simulator

The first step in importing utilities into the Market Simulator is to create a new study or open an existing study. Open the SMRT software by clicking Start | Programs | Sawtooth Software | Sawtooth Software SMRT. To create a new study, select File | New, and browse to the directory in which you want to save all study-related files.

Remember: The SMRT and SSI Web systems work independently, so you need to establish a new project name and project file for the SMRT system to analyze your conjoint data.

Specify a study name, and the extension ".SMT" will automatically be added. If you own more than one conjoint analysis license, you are asked to specify the study type (i.e. ACA, CVA or CBC).

To open an existing SMRT study (not an SSI Web study), select File | Open, and browse to the directory containing the studyname.SMT file. Double-click the studyname.SMT file. If attributes and levels definitions exist in the study, they must match the attributes and levels for the conjoint data to be imported.

After you have opened the study, choose Analysis | Run Manager. The Import option on the Run Manager dialog lets you import conjoint utility (part-worth) data from text-only files for use within the Market Simulator. You can import multiple sets of conjoint utilities which become separate selectable runs. The utility data can come from a number of formats or sources:

HB Utilities (*.hbu)

Hierarchical Bayes utilities generated by CBC/HB, ACA/HB, or Adaptive CBC (see the HB manuals for data layout). If importing an .HBU file, the attribute labels are read from the header section of the .HBU file.

ACA (*.utl)

part-worth utilities from the ACA system (see the ACA manual for data layout) or ACA v4.x. If you import a studyname.UTL file, labels for the attribute levels are imported from the studyname.ACA file. If a studyname.ACA file does not exist, default attribute and level labels are assigned.

CVA Utilities (*.utl)

part-worth utilities from the CVA v2.x system. If you import a studyname.UTL file, labels for the attribute levels are imported from the studyname.CVA file. If a studyname.CVA file does not exist, default attribute and level labels are assigned.

Latent Class (*.pxx)

Latent Class utilities generated by the CBC Latent Class v2 Module (see the Latent Class manual for data layout). When importing Latent Class utilities, the data are read from two files: *.Pxx (e.g. studyname.P05 for a 5-group solution), which includes information about respondents' probabilities of membership in each group; and the *.LCU file which contains the average utility estimates for each group. Note that the .Pxx file is not generated by default, but must be requested by a parameter in the .PAR file prior to generating the Latent Class run. During the import process, individual-level utility data are generated by multiplying the probabilities of membership by the vector of utilities for each class. If importing Latent Class data, the attribute levels are read from the header section of the .LCU file. If linear specification of quantitative attributes has been used, there must be an accompanying .VAL file in the same directory.

You can also merge the latent class membership for use as banner points and/or filters. To merge group (class) membership, select File | Merge Variables | Add... and then choose Latent Class 2.x Group Membership (*.Pxx). SMRT assigns each respondent to the group for which he/she has the highest probability of membership (ties broken randomly). To use group membership from latent class as a banner point, you must first specify the merged variable as a Custom Segment.

Generic Conjoint (*.hbu)

With the Generic Conjoint .HBU format, you can import conjoint utility data generated in any other way or software program, including main effects, first-order interactions or linear term specifications, as long as the attributes and levels do not exceed the capacity of your system and the data are formatted as an .HBU file. The generic .HBU format assumes one case per respondent (not "Draws" as can be an option for Hierarchical Bayes estimation).

Data from text-only files are read with 15 significant digits of precision.

When utility run data are imported, four files are modified or created:

Studyname.UCS (a binary data file containing respondent numbers and conjoint utilities)

Studyname.QNR (a binary data file containing attribute level labels and questionnaire settings)

Studyname.DAT (a binary data file containing respondent numbers and any segmentation information)

Studyname.IDX (a binary index file describing the layout of the Studyname.DAT file).

If your study had no respondent data prior to importing a utility run, a list of respondent numbers (corresponding to your utility run) is created in a Studyname.DAT file. If your study already included respondent numbers and data, then the conjoint part-worths are written to the .UCS file and it is assumed that corresponding respondent records are available in the .DAT file (if applying banner points, filters or weights). If no attribute labels are provided, SMRT provides default labels. If conjoint attributes and level labels exist in your study prior to importing conjoint utility data, those definitions are preserved and the utilities to be imported must match that layout. If there is a mis-match between the number of imported attribute levels and the number of existing levels in the study, SMRT will issue a warning message.

If your text-only conjoint data file included segmentation information you want to import, you must merge those data separately using File | Merge Variables.

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Exporting Utilities into Text-Only Format

The Export option lets you export conjoint utility data from the binary .UCS file into a text-only .HBU format. Data are written with up to 5 decimal places of precision.

Text-only conjoint data in an .HBU format can be imported for use in the Market Simulator.