With Max-Diff, survey respondents are shown a set of the possible items and are asked to indicate the best and worst items (or most and least important, or most and least appealing, etc.).
Implementing MAX-DIFF task in a survey:
Please find attached sample survey that demonstrate a MAX-DIFF section in it.
You can view this next link that shows how to import an external survey into your account:
As part of the implementation you'll need an external excel file containing the needed rotations for the MAX-DIFF. Please find attached the sample excel file, that use as a subject store in the sample survey.
When creating your script, don't forget to load your MAX-DIFF excel file as a subject store to your script, so you can use it. 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