MaxDiff is an approach for obtaining preference/importance scores for multiple items (brand preferences, brand images, product features, advertising claims, etc.) using marketing or social survey research. With MaxDiff, respondents are shown a set (subset) of the possible items in the exercise, and are asked to indicate (among this subset) the best and worst items (or most and least important, etc.). The MaxDiff custom element allows you to easily add the statements and MaxDiff design to your survey.
1: Design File Setup
The MaxDiff design file must be a tab-delimited file saved in .dat format. The example shown below illustrates the setup required for the file. In our example we've set up the design in an Excel file for easier viewing, but we must change it to tab-delimited (.dat) after the design has been configured. Read more below.
1. Version: The first column in the design file, containing the number given to identify the group of sets/tasks.
2. Set: The second column in the design file, containing the number given to identify the group of items.
3. Item [1,2,...]: Each "Item" column becomes a statement place in the MaxDiff question, and the statement is determined by the number.
4. Ordering: These numbers correspond with the statements for the question.
To change this file to a tab-delimited file, select "Save as", and select "tab-delimited (.txt)" format, then Save.
Then edit your file name and manually replace ".txt" with the ".dat" extension and save.
The result will be the tab-delimited .dat file required by the system:
If you are converting an Excel file to a tab-limited format while using an Apple computer, new line characters may save with the wrong type of newline character and a workaround may be needed to properly format the file for usage.
2: Uploading the Design File
To upload the design file while in the survey builder, open the "Actions" menu and select "Upload System Files".
In the file manager, click on the "Add Files" button to select the file, or simply drag and drop the file into the space below the button. Multiple files can by added at once.
Once the file has been selected it will appear in the file manager. Select "System Only (Root)" location option, then click "Upload".
Once a file has been uploaded it cannot be removed or deleted at this time. Click "Remove" to remove the file before it's uploaded.
Once uploaded, copy the name of the file. This name is required for setting up the element.
3: Adding a MaxDiff-File Element
The MaxDiff File Element is only available on the following servers:
For all other servers use one of the following methods to create a MaxDiff Question:
To insert a MaxDiff-File element, add a new survey element, select the "Custom" tab and choose "MaxDiff-File". Then click "Insert".
A MaxDiff-File "blackbox" element will show in the stage area. A corresponding icon will also show in the question tree. Click "Edit Blackbox" to add question content and define the settings.
4: MaxDiff-File Blackbox Setup
An overview of each field in the blackbox element is provided in the table below this example.
|Label||The question label for the MaxDiff-File element.|
|Header Title||The question text for the MaxDiff that's shown to respondents.|
|Best Text||The best case/positive text, displayed in the left column.|
|Worst Text||The worst case/negative text, displayed in the right column.|
|Design File Name||The name of the file, copied from the file manager.|
|File Delimiter||Default to "\t" to parse tab-delimited file.|
|Number of Versions||
The number of versions being tested in the MaxDiff. This number must exactly match the design file in order for the element to calculate correctly.
|Number of Tasks||The number of sets/tasks being tested in the MaxDiff. This number must exactly match the design file in order for the element to calculate correctly.|
|Item Statements||The statements (i.e., attributes) for the MaxDiff, entered in order. If the highest attribute number is 11 in the design file, there must be exactly 11 statements/attributes defined here.|
|Number of Items Shown||The number of items shown at each task.|
|Randomize Tasks||Enter yes to randomize the tasks; enter no to display the tasks in order.|