If you would like to prevent duplicate responses to your survey, you can select either Cookie-Based or IP-Based duplicate protection. Before you choose an option it's best to review how each of these options work so you can make an informed decision!
How Does Duplicate Protection Work?
The first thing to know about both duplicate protection methods is that they only take effect if the initial response proceeds past the first page. For IP-Based Duplicate Protection, the second and later attempts need to submit the first page before they receive the duplicate protection message.
Second, it is important to note that both duplicate protection methods will prevent survey respondents who only recorded a partial response (as well as those that are disqualified) from returning to complete the survey. If you wish to allow survey respondents to return to partially completed responses, we recommend enabling Save and Continue as this will return the respondent to the same session thus trumping the duplicate protection settings.
Third, each method works a little differently and thus has its strengths and weaknesses. Read on to learn more!
How Does Cookie-Based Duplicate Protection Work?
Cookie-based Duplicate Protection works by storing a small piece of data on the respondent's web browser. In this way, one response per browser per device is allowed.
What Is a Cookie?
A cookie or an HTTP cookie [1] (also called web cookie, Internet cookie, browser cookie or simply cookie), is a small piece of data sent from a website and stored in the user's web browser. Every time the user loads the website, the browser sends the cookie back to the server to notify of the user's previous activity. Cookies were designed to be a reliable mechanism for websites to remember information (such as items added to the shopping cart in an online store) or to record the user's browsing activity (including clicking particular buttons, logging in, or recording which pages were visited in the past). Cookies can also store passwords and other previously entered form content such as an address.
Cookies Are Not a Fail-Proof Duplicate Protection Method
Because cookies are set on a specific browser on a specific device, if a respondent accesses the survey from more than one device or browser, they would be permitted to enter more than one response.
In addition, tech-savvy respondents can use their browser's option to clear their cookies if they are really set on recording more than one response.
Does the SurveyGizmo's Duplicate Protection Cookie Expire?
Yes, the duplicate-protection cookie expires after 90 days.
Using User Agent to Determine if a Respondent Used Another Browser/Device
The User Agent field which includes information, found on the Details tab of an Individual Response, can be used to see if two responses were recorded on different devices. The User Agent field indicates the device and browser used.
How Does IP-Based Duplicate Protection Work?
IP-based Duplicate Protection allows one response per IP address.
IP-Based Duplicate Protection Isn't Always An Option
Because some environments share a single IP address, e.g. corporations, universities, hospitals, this option is not ideal if distributing your survey to multiple recipients in an organization that might be sharing an IP.
Review Respondents' IP Addresses In Individual Responses
IP address is stored by default (unless your survey is set to anonymous). You can review IP addresses for each response on the Details tab of Individual Responses.
Setup
To set up duplicate protection:
- Click Tools > Response Settings.
- Choose between Cookie or IP based Protection
- Customize your duplicate messaging and Save Settings.
Alternative Options For Preventing Duplicate Responses
- Email Campaigns - If you know who your contacts are, using an email campaign to send out your survey will automatically prevent duplicate responses.
- Login/Password Action - If you know who your contacts are you can also set up your survey so that respondents have to log in thus preventing multiple responses per contact.
References
1. HTTP cookie. In Wikipedia. Retrieved February 1, 2016 from http://en.wikipedia.org/wiki/HTTP_cookie
— Mike.cordeiro on 05/05/2020
@Kurt: Thank you for your question!
Regrettably duplicate protection must be turned on individually per survey as there is not currently a way to toggle Duplicate protection at the account level.
I hope this helps!
Mike
Technical Writer
SurveyGizmo Learning and Development
— Kurt on 05/04/2020
Hello,
Is there an option to turn duplicate protection on as an account-wide setting/default, rather than within each individual survey?
Admin
— Dave Domagalski on 11/18/2019
@Niklas: Thank you for your note and question!
I’m afraid that the cookie cannot be updated along the way with the currently built-in cookie protection. A possible alternative that should work for the situation that you described is the sguid URL variable:
https://help.surveygizmo.com/help/sguid-the-url-variable
This variable makes a link unique, one-time-use, and has the added benefit of saving the respondent’s progress.
I hope this helps!
David
Technical Writer
SurveyGizmo Learning & Development
— Niklas on 11/18/2019
The cookie duplicate protection generally works fine. But we've had a few cases where a respondent has been thrown out of a survey midway (not disqualified - just thrown out for an unknown browser error) and then they can't get back in. Would it be possible to update the cookie along the way, so it's only active after a disqualification or a complete? In a perfect world it would track the progress, so in case the respondent abandons the survey, they'd get back to where they left (if not disqualified).
Admin
— Dave Domagalski on 11/14/2019
@Tamara: Thank you for your question!
In my testing, I am seeing the duplicate protection working with an anonymous survey. I have tested with both the cookie and IP based protection.
I hope this helps!
David
Technical Writer
SurveyGizmo Learning & Development
— Tamara on 11/13/2019
So it looks like you can't have an anonymous survey AND duplicate response protection?
Admin
— Dave Domagalski on 09/05/2019
@Jacob: Thank you for your question!
I'm afraid that the option to filter out duplicate responses by IP is not available in the Standard Report. However, you will find this option in the Comparison and Profile Reports, as well as the Fall Off Statistics.
I hope this helps clarify!
David
Technical Writer
SurveyGizmo Learning & Development
— Jacob on 09/05/2019
Is there an option to filter out duplicate responses in Reports (like filtering duplicates by IP address from a CSV/Excel Export)?
Admin
— Dave Domagalski on 06/28/2019
@Jeff: Thank you for your question!
Assuming that you are utilizing cookie-based duplicate protection, clearing cookies on your browser will allow additional responses.
If you are using IP based protection, this will only allow one response per survey from any given IP. This is not recommended in scenarios where multiple individuals in the same location need to take the survey.
Please don't hesitate to reach out to our Support team if you run into any trouble!
https://help.surveygizmo.com/help/surveygizmo-support-hours
David
Technical Writer
SurveyGizmo Customer Experience
— Jeff on 06/28/2019
hi- I want to set up 'no duplicates' but it appears that when I do, neither I nor any of my peers who have tested the survey pre-launch can take the survey now. How do I resolve that so all of us can take the official survey once it's live?
Admin
— Dave Domagalski on 08/06/2018
@ TKP2: Thank you for exploring SurveyGizmo documentation content!
I'm afraid that duplicate protection does not work across surveys. The feature is intended to prevent duplicate responses to a single survey.
One potential workaround for your scenario could be to build a 'gateway' survey where all respondents land initially. This is the survey that would have the duplicate protection enabled.
Then, using logic conditions on the gateway survey, you could direct respondents to their respective surveys via the URL Redirect Action:
https://help.surveygizmo.com/help/redirect-to-a-website
I hope this helps!
David
Documentation Specialist
SurveyGizmo Customer Experience
— Cambridge on 08/06/2018
Hi, is it possible to prevent duplicate responses across a number of surveys? Due to the number of quotas we have applied, it is not possible to simply use share links to send to multiple groups so we have had to split into multiple identical surveys, but now it seems we can only prevent duplicates within each individual survey.
Admin
— Dave Domagalski on 05/18/2018
@Chelsea: Thank you for your suggestion! It's something that I can share with our Product team as a potential future upgrade.
In the meantime, there may be some alternatives that you could consider. If you are sharing your survey via email, or otherwise have respondents' email addresses available, there are a couple of potential options:
- You can send your survey via SurveyGizmo's Email Campaign feature:
https://help.surveygizmo.com/help/share-survey-via-email
This tool generates a unique, one-time-use link for each email address that is added.
- You can utilize the 'sguid' URL variable:
https://help.surveygizmo.com/help/sguid-the-url-variable
This URL variable allows you to generate your own unique, one-time-use links.
I hope this gives you some options!
David
Documentation Specialist
SurveyGizmo Customer Experience
— Chelsea on 05/18/2018
Suggestion...It would be really nice if you could prevent duplicate responses by the users e-mail address (obviously would have to make sure that was a required field in your survey). Doing it via cookies isn't really sufficient based on my experience.
Admin
— Dave Domagalski on 03/19/2018
@Jared: Great question!
SurveyGizmo has a reserved URL variable that, when used, allows for duplicate protection:
https://help.surveygizmo.com/help/sguid-the-url-variable
Once you familiarize yourself with the sguid URL variable, you can also use a different URL variable as your sguid:
https://help.surveygizmo.com/help/sguid-the-url-variable#sguid-alias-use-a-different-url-variable-as-a-sguid
I hope this helps!
David
Documentation Specialist
SurveyGizmo Customer Experience
— Jared on 03/18/2018
Is it possible to manage duplicates with a URL variable i.e. the URL variable must not have been used before?
Admin
— Dave Domagalski on 10/12/2016
@Eseiver: Thank you for taking a look at SurveyGizmo Documentation!
SurveyGizmo offers an option to filter out duplicate responses (from a CSV/Excel Export) that were recorded from the same IP address. Depending on how duplicates may have been recorded, this could be an option:
https://help.surveygizmo.com/help/excel-export#filter-tab
If the duplicate responses are not IP based, duplicates can be removed via Excel from a CSV/Excel export of your survey data.
I hope this helps!
David
Documentation Specialist/Survey Explorer
SurveyGizmo Customer Experience
— Eseiver on 10/11/2016
In addition to preventing duplicates, is there a way to indicate or resolve duplicates? Similar to how we can mark responses as 'disqualified'.
Admin
— Bri Hillmer on 08/15/2016
@John: Thanks for your feedback! I'll pass this along to our customer experience team for discussion of possible future improvements!
Bri
Documentation Coordinator/Survey Sorceress
SurveyGizmo Customer Support
— John on 08/15/2016
It would be great if we could set the expiration date for the cookie to 30,60,90......and never.