Getting Started: Overview of CBC Software
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CBC is a component within the SSI Web suite of Internet interviewing products. CBC is used for conducting Choice-Based Conjoint (CBC) studies over the web, in non-web "CAPI" interviewing mode, or via paper-and-pencil questionnaires. CBC questions are usually integrated within a longer SSI Web questionnaire that includes other standard survey questions. The number of additional questions that can be added depends on your license. A CBC study can include additional standard survey questions that collect up to 50 data fields. An unlimited number of additional questions can be used if the largest CiW interviewing license is acquired.

CBC studies are used for learning about respondents' preferences for the combinations of features that make up products or services. CBC analysis can help with (among other things) product design, line extensions, pricing research, and market segmentation.

Your license entitles you to free technical support via phone or email. We encourage you to contact us at support@sawtoothsoftware.com or +1-801-477-4700 if you cannot find the answer to your problem or question in this documentation. We are available Mon-Fri, 7:30 am to 5:30 pm Mountain Standard Time. (Note: we provide full technical support for composing and testing your Internet survey on your local PC, and provide written instructions on how to install your questionnaire on your server. We cannot take responsibility for or be expected to provide technical support to debug any customized HTML or JavaScript you may add to your survey. You are also responsible to make sure that Perl is running, a database is available, and that you can run Perl (CGI) scripts on your web server. We can provide some assistance related to SSI Web's use with your server once the fundamental Perl functionality and a database is in place.)

A sample CBC questionnaire (tut3.ssi) and supporting files are available in the \Samples folder within your SSI Web installation. You can easily access this example study by clicking Help | Sample Studies. This questionnaire lets you see an example of a CBC survey and investigate how it is set up.

If you know a little HTML (which is not necessary to use CBC), you can employ some "tricks" to help you customize the look of your survey beyond the standard options provided by the software. By opening the sample study and looking at the settings and text we've used, you can become familiar with some of the possibilities.

Using CBC requires the following skills and knowledge base:

·The analyst managing the survey should know the basics of conjoint analysis, including defining attributes and levels properly, correctly phrasing the questionnaire text and response scales, interpreting the part-worth utilities, and running simulations. It is not necessary to be a statistician to use our software effectively, but knowledge of basic statistics for market research is highly recommended.  
 
 
·The questionnaire is first composed locally on a PC running under Windows XP, Vista, or Windows 7. The individual inputting/formatting the survey should have working knowledge of standard Windows applications such as word processing, Web browsers and/or spreadsheets. Though it is not necessary, some knowledge of HTML is valuable.  
 
 
·For web-based data collection, you may use our survey hosting services. You can also host surveys on your own (one must have access to an Internet/intranet server running Perl 5.007 or later, with a database). This can be on your company's own Web server, or your ISP's (Internet Service Provider's) Web server. SSI Web is able to automatically upload the files needed to perform data collection on your server. But, in some cases the user must know how to use FTP software to create directories, upload files to those directories, and set permissions on the files and directories. Click here to receive detailed instructions on the directories, files and permissions.  

Relationship between CBC and SMRT

CBC is used for designing, creating, and fielding CBC studies (either web-based, non-web "CAPI" interviewing, or paper-and-pencil modes). But you analyze the CBC data using the Online Simulator (or the older SMRT software). SSI Web and SMRT are installed and run independently--but they share a common file format (*.CHO), enabling the SMRT software to easily read the data resulting from a CBC study.

If you don't already own SMRT software, you receive a special copy (along with a manual) to analyze your CBC data.


Steps in Conducting a CBC Study

1) Formulate attributes and levels and type them into the CBC interface.

2) Make decisions regarding your study design: decide how many product concepts to display per choice question (task), whether to include a "None" option, and how many choice tasks to field in your study. Using the point-and-click CBC interface, add those CBC questions to your SSI Web study.

3) Test your questionnaire in preview mode, by using the Local Test Server included in SSI Web, or by uploading the files to your Web server. Make modifications and re-test.

4) Decide how many unique versions of the CBC questionnaire to use in your overall design (default is 300). If using paper-and-pencil data collection, it is common to use a few to a dozen design versions. Generate the design. Using the Test Design module, test the CBC design to make sure the design is efficient to estimate the part-worth utilities (main effects).

5) If using web-based data collection, upload your study to an Internet server, and continue testing--by yourself, with colleagues, and later preferably with a small number of pilot respondents. Receive feedback from colleagues and pilot respondents. Examine the data to make sure all data are being stored properly using the Admin Module, and by downloading the data to your hard drive. Export the data to a text-only *.CHO file. Estimate part-worth utilities using HB (hierarchical Bayes) or Latent Class. Import the results into the SMRT software package or the online market simulator for analysis.

6) After ensuring that your CBC questionnaire works properly, that the data are being stored correctly, and that your design is not deficient, invite respondents to take the survey.

7) Monitor the data collection using the Admin Module. Download the data, and then Prepare files for analysis within the SMRT system (or the online market simulator). See the SMRT manual, or online help within the SMRT software for documentation regarding CBC analysis.