One of the strengths of the CVA system is its ability to generate experimental designs (the combinations of attribute levels to show to respondents) in an efficient and easy manner. Also, multiple versions (up to 10) of the questionnaire may be generated, so different respondents see different combinations of attributes within the conjoint tasks.
Some researchers may wish to export the design, to examine ahead of time the combinations that will be asked of respondents (and perhaps to perform additional analysis regarding the design).
Other researchers may have developed questionnaire designs using other software and wish to import those designs for fielding within the CVA system. They can do this through CVA's Import Design capability. Another use of the Import feature is to add holdout conjoint questions ("fixed" CVA questions that are asked exactly the same way across all questionnaire versions) in your study design.
For all purposes, the design file uses the same comma-separated (.CSV) layout. A .CSV file can be directly opened and saved with Excel, and the examples below assume you are working with the comma-separated file in Excel. (If using a text editor, the values in the file are separated by commas.)
If you import a design, any existing design will be overwritten.
Import/Export File Format
The file format is as follows.
Indicates the questionnaire version.
Indicates the task (conjoint question) number.
Indicates the concept number. Designs showing one product concept at a time always have concept #1. Designs showing two product concepts at a time (pairwise presentation) have concept #1 and concept #2.
Columns 4 through n
Shows the attribute levels associated with the current concept, task, and version number.
In the example below, only two versions of the questionnaire are shown. There are three attributes in this study.
Pairwise (Two-Concept) Presentation:
In the example below, only two versions of the questionnaire are shown. The design reflects pairwise presentation layout (two concepts per question). There are three attributes in this study.
The version must start with 1 and proceed in that order.
The number of versions and number of tasks must match the number of versions and tasks specified in the software.
The number of concepts must be constant across all tasks. The number of concepts must match the number of concepts specified in the software.
Any prohibitions specified in CVA will not be checked against the imported design.