Home Features External reference variable

What is an external reference variable?

An external reference variable is used to pass data to the survey and associate responses with their respondents. You can assign an ID number or other information that will uniquely identify a respondent to the ext_ref variable. When the results are collected, the ext_ref variable is captured and stored with the other data. An external data reference can also be added for each survey participant while distributing emails.

The &ext_ref variable is automatically captured in the raw response data. You can use it later, along with survey reports to analyze data. While using a reference variable in QuestionPro Surveys to capture external data, below are some of the points to keep in mind.

Example of external reference variable in surveys

Consider a University that wants to conduct a course evaluation survey. You can append the external reference parameter (ext_ref) with the URL, as shown below.

You can also use ext_ref to create a survey that identifies unique respondents.

How to use the ext_ref with the QuestionPro email list manager?

If you are using the email list management interface to send out a survey email, add the following tag to your survey invitation.


Note: The mail merge tags are special variables that are used in email list management to track the email addresses of respondents. Append &ext_ref=xxxx at the end of the mail merge tags.

Uses of external reference variable in surveys

Advantages of capturing external data

How to use external reference variable in your surveys?

Learn how to set up and use this feature with our help file on custom variables.