Passing Information and Linking Surveys

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How do I pass information, such as a respondent number from a panel company, into a Sawtooth Software survey?

In this article we will explain how to pass information into and out of a survey.

Researchers sometimes depend on panel providers to supply a pool of prospective respondents. When you use a panel, you need to capture a panel ID and return it so respondents get credited for taking your survey.

Furthermore, some users may wish to link their Sawtooth Software survey with another survey platform or a different Sawtooth Software survey. Passing information through a link is helpful in this situation so you can merge the data later on.

There are three important parts to setting up this connection for panel providers and linked surveys: the Start question, the Terminate question, and the Sawtooth Software survey entry link. We will be review each of these sections as seen in Lighthouse Studio version 9.6.1.

If you are using the Discover platform, we have another video of instructions in our help documentation under the Survey Links sections (available here:

How to Create your Link Variables in the Start Question

First off, we want to go into the settings for the Start question. There are several ways to get there but we are going to click the pencil icon and double-click on the question named “Start”. In the Start question settings we can see tabs for Passwords Fields and Pass-in Fields. Both of these options, using either passwords or pass-in fields, will alter the link for your survey to allow information to be passed into your survey.

You can add passwords by entering a Field Name under the Password Fields tab. Passwords can also be used to prevent respondents from taking the survey several times. Passwords can either be user-specified or you can make a pre-defined password list. For simplicity, we recommend using the same field name as the unique identifier you intend on passing through. For example, a panel provider may use “PSID”.

If you know the list of pre-defined passwords you would like to use, you can specify the passwords by clicking on the key icon “Password Data”. Keep in mind that you will need to change the default Max Respondent column to a larger number if you intend on having more than one person use the same password. Panel providers will often create unique passwords for each respondent themselves. In this situation, you can still use the password option by checking the “Allow respondents to define their own passwords” under the Settings tab for the Start question. Panel providers will typically insert their unique password for each respondent in the "one-click link" you provide to them. When the "one-click link" is clicked, it will record the password data, skip the start question, and send the respondent to the first question after the start question.

If you do not care about a respondent being able to re-enter the survey where they left off, you can use the pass-in field option. Similar to the password field, you will likely want to use the same field name as the unique identifier you intend on passing through. For example, a panel provider may use “ID”. Unlike passwords, pass-in fields do not restrict access to the survey.

How to Set up Your Terminate Question

Most panel providers will give you three exit links which would include a link for (1) completes, (2) disqualified, and (3) over-quota respondents. If you do not have a quota in your survey, you do not need to use the over-quota link. If you do not have a question that is programmed to skip and disqualify a respondent, you do not need to worry about the disqualified link. For the sake of the example, we will assume your survey requires all three exit links.

You will need to make three separate Terminate questions at the end of your survey, each separated by a page break. The Terminate question for completes should always be the first one listed in the survey. If respondents are following the natural flow of the survey, they will hit this completes Terminate question first and be marked as complete. You will need to insert skip logic for your quotas and or screener questions to reach the other Terminate questions.

When you enter the completes Terminate question, your first step should be to check the status under the Settings tab. The completes setting should have the terminate status of "Qualified/Complete".

Next, you will want to go to the Link Settings under the Settings tab. When you check the option, “Link to a Questionnaire or Website” it will allow you to insert your completes exit link in the Web Address URL box.

Keep in mind that when you use a re-direct link in your Terminate question, it will warn you that text in the question will not be shown to respondents. The moment a respondent hits a Terminate question they are immediately sent to wherever the link directs. If you would like to have text such as “Thank you for taking my survey”, you can insert it into a Text question before the Terminate question. However, using a Text question before your Terminate question may raise the risk of respondents thinking they are done with survey and that it is safe for them to close their browser. If they do this, they will never hit the Terminate question which marks them as complete, so they will end up being an incomplete. Chances are, your panel provider may have some “Thank you” text for when the respondent finishes the survey in their platform.

Now we will want to reference the pass-in variable/password we created in the Start question. Anything passed through the entry link using the pass-in variable will be saved in the database under the pass-in variables name. The panel provider will want that information back so they can check how may respondents completed the entire survey. In the exit links provided by your panel provider, you may see link ending with PSID=XXXX or PSID=<psid> to clarify where you need to insert the ID for each respondent. Delete the XXXX or <psid> and instead insert the script, [%NameofYourPassword/PassinVariable%]. The [% %] is a bit of Sawtooth script that allows you to reference our database to retrieve the value of the pass-in variable for the respondent. If you named your pass-in field "PSID", your exit link may end with PSID=[%psid%]. You will need to repeat the steps we took for the complete Terminate question in the disqualified and over-quota Terminate questions as well.

If you are simply linking one survey to another survey (on our platform or another), you can insert the next survey’s access link into the “Link to a Questionnaire or Website” input box. The one-click link will allow you to pass information, such as a unique ID or a respondent number, through the link into the next survey. This linked information is important for confirming respondent data in multiple datasets.

It is always good to check that the disqualified and over-quota Terminate questions are using the Disqualified terminate status option under the question settings. An easy way to test this is to use our built-in data generator with your quotas set up with a low quota limit. This will allow you to test if everything is working properly before the survey goes out to real respondents.

How to Modify Your Sawtooth Software Survey Entry Link

The only way the Sawtooth Software survey can take in the unique ID/password and send it out through the exit link is if the information is provided in the one-click link for the Sawtooth Software survey. If you try to attach any variables to the access or one-click link without first creating a pass-in field/password, you will generate a Sawtooth Software error and the information will not be passed through. When you create a pass-in field/password, the name of the variable will automatically be attached to the one-click link when you upload to the server.

You will need to provide your panel provider with the one-click link that is shown when you upload your survey to a server. Your one-click link will look similar to the following example.

Your panel provider will need to replace all instances of VALUE with the actual value for that password/pass-in field. They will need to do this for every single respondent. The link for the first respondent using the example above could replace VALUE with their ID 1104656.

Now when the respondent hits the panel provider’s redirect page, they will be sent to the Sawtooth Software survey which will take the 1104656 from the link and insert it into the pass-in field named "ID". When that respondent hits a terminate question the "ID" will be passed back to the panel provider. Remember that pass-in fields have no verification to them, so they can be left blank or be identical for all respondents if needed. 

This concludes this brief tutorial on how to pass information into and out of a survey. If you have further questions, please refer to the Lighthouse Studio help documentation or send an e-mail to