A Conjoint model is designed to display a rotating set of items on screen, where in each rotation, some of the items details (for instance like the items order, names, prices and / or other attributes) are changed, and the respondent select one item each time (at each rotation display).
The main structure of a Conjoint section would be in a Loop chapter (Click Here to learn more about Loops in SurveyToGo). Each iteration in that loop displays a screen with a specific items combination (that is based on the Conjoint Design).
The standard Conjoint Design would be an excel file that will usually include the following data:
- A "Version": This is a numeric value that is randomly selected in the interview and indicates what sets of combinations to show in that interview.
- A "Set" (sometimes also called a "Task"): This indicates an iteration index in the Conjoint loop. Each Version should have the same number of Sets (iterations).
- Labels and Codes Columns of the items that need to be pulled and displayed on screen in each Conjoint rotation.
In this article we will present two sample surveys that offers two different ways to design and implement a Conjoint model.
In this Conjoint sample, respondents are presented with a set of brands in various combinations of packaging and pricing and are asked to indicate their selection in each combination.
The Conjoint design includes 4 versions and 4 sets in each version.
In addition, the items list in the design includes a total of 7 items (an "item" is a label of a brand and a pack size), and in each set, 3 items are displayed with their prices, according to the Conjoin Design.
In this Conjoint sample, respondents are presented with a set of Cars items that have different attributes (Price, Engine, Fuel type, Millage). and are asked to indicate their selection in each combination.
This Conjoint design includes 2 versions and 5 sets in each version.
In addition, the items list in the design includes a total of 5 car brands, and in each set, 3 brands are displayed with their attributes according to the Conjoin Design.
The main difference between the two samples:
In Sample #1, the items displayed are not "divided" into separate attributes, besides the price value. Meaning, there are 7 different items overall, and the conjoint logic is to display in each set (each iteration) 3 items out of those 7, with changing prices. And so, the Conjoint question in this case, is a single choice question that holds the exact same items list (with the same 7 items), and in each iteration, the items are filtered based on the relevant Set from the Conjoint design file.
In Sample #2, the "main" items are the cars, and those have additional attributes. The rotating combination in each set display different values for those attributes. The attributes are displayed in a Grid render mode, where the attributes names are the headers and the actual attributes values (that are changing in each set) are in the Grid's data cells. So here, the Conjoint loop includes two different question - The first has its options list constructed as a Grid (the options are displayed in multiple columns). The options themselves are all defined as "Not selectable", as those are for display only. The second question has the actual responses to code. It is structure in a way that each radio button will appear under a specific column of the grid (so both questions are displayed in the same page).
Importing and Testing the Conjoint samples:
In each one of the attached zip files, you will find 3 files:
- And SRV file - this is the sample survey. Import the srv file into your organisation. You can view this next link that shows how to import an external survey into your account: http://support.dooblo.net/entries/22388573-How-to-import-a-survey
- An Excel file - this is the conjoint design that should be added as a Subjecy Store to the studio and survey. To learn more about additional subject store, please view this next link: http://dooblo.zendesk.com/entries/22793802-How-to-use-an-excel-file-as-a-data-list-in-a-survey
- An "images" zip file: This holds images of the items that are destined to be shown in the Conjoint section. To include images in the sample, extract the images from the zip file and upload those to the survey script through the survey's Advanced tab -> Edit Survey Attachments -> New.
- Note that the images display in these samples is done through an Attachment source. To learn more about attachment source, view this link: http://support.dooblo.net/entries/28459612-How-To-Dynamically-Display-Answer-Images