Implementing Conjoint in SurveyToGo

Overview

A Conjoint model presents respondents with a series of item combinations, where one or more attributes—such as item order, name, price, or other characteristics—change between each screen. For every combination displayed, the respondent selects their preferred item.

In SurveyToGo, a Conjoint task is typically implemented using a Loop Chapter, where each iteration represents a single conjoint task (or set). The content displayed in each iteration is driven by a Conjoint design file.

A typical Conjoint design is stored in an Excel file and includes the following information:

• Version – A numeric value that is randomly selected for each interview. The selected version determines which set of combinations will be presented to the respondent.

• Set (also referred to as a Task) – Identifies the loop iteration. Each version contains the same number of sets.

• Item labels, codes, and attributes – The information required to display the appropriate items and their attributes for each set.

This article includes two sample surveys that demonstrate different approaches to implementing a Conjoint model in SurveyToGo.

Sample 1: Product Selection

In this sample, respondents are presented with different combinations of brands, package sizes, and prices, and are asked to select their preferred option in each set.

The Conjoint design contains:

• 4 versions

• 4 sets per version

• 7 products (each product represents a unique combination of brand and package size)

During each set, 3 products are displayed along with their corresponding prices, as defined by the Conjoint design.

Implementation

In this approach, each product is treated as a single item. Apart from the price, the product attributes are not separated.

The survey contains a Single Choice question with all seven products defined as answer options. During each loop iteration, the answer list is filtered so that only the three products defined for the current set are displayed.

Sample 2: Car Attributes

In this sample, respondents evaluate different car brands with varying attributes, including:

• Price

• Engine

• Fuel Type

• Mileage

The respondent selects their preferred car in each set.

The Conjoint design contains:

• 2 versions

• 5 sets per version

• 5 car brands

During each set, 3 car brands are displayed with attribute values defined by the Conjoint design.

Implementation

In this approach, the car brand is the primary item, while the remaining values are displayed as attributes.

The Conjoint section contains two questions:

1. A Grid question that displays the car attributes. The grid columns represent the car brands, while the rows display the attributes. The grid cells contain the attribute values for the current set. All grid options are configured as Not Selectable, since they are used for display only.

2. A Single Choice question that captures the respondent's selection. The answer options are aligned beneath the corresponding grid columns so that both questions appear together as a single conjoint screen.

Key Differences Between the Samples

Sample 1

• Products are treated as complete items.

• Only the displayed products and their prices change between sets.

• A single filtered Single Choice question is used.

Sample 2

• Products consist of a main item (the car) and multiple changing attributes.

• Attributes are displayed in a grid layout.

• A separate Single Choice question records the respondent's selection while the grid provides the visual comparison.

Importing and Testing the Samples

Each attached ZIP file contains the following:

• Survey (.srv) – Import this file into your organization.

• Conjoint Design (Excel) – Add this file as a Subject Store and associate it with the survey.

• Images (.zip) – Contains the images displayed in the Conjoint questions.

To use the images:

1. Extract the image files from the ZIP archive.

2. In SurveyToGo Studio, open the survey.

3. Go to Advanced > Edit Survey Attachments > New.

4. Upload the extracted images.

The sample surveys display the images using an Attachment Source.