Prevent Duplicate Submission in Forms & Surveys

Blocksurvey blog author
Written by Wilson Bright
May 18, 2024 · 5 mins read

Data collection without duplicate prevention would be a nightmare, How? As a Data collector, you spend time crafting a perfect survey and are ready to get insights from the data you're going to collect. And we all would have been excited to open a survey and share our opinions but then halfway through the survey or even after submitting the survey, we might realize that you have actually done this before. It’s not only about wasting our time to retake the survey without realizing that we have done it before but this duplicate data can really mess up the data collector’s insight.

Imagine a survey creator sending out rewards to boost participation. There could be bots or even the users might make multiple attempts to get higher rewards. So keeping this in mind and to tackle duplication BlockSurvey brings you this awesome feature “Prevent duplicate submission”.

Why prevent duplicates and how does it help?

Duplicates are like bad ingredients in a recipe. They mess up the whole dish! Here's why preventing duplicate submissions is crucial:

  • Less/No Cleaning, More Analyzing: No more spending hours looking for and removing duplicate data! You can focus on what really matters - analyzing the good data and getting valuable insights.
  • Happy Users: Users won't waste time accidentally resubmitting surveys, leading to a smoother experience for everyone.
  • Fair Reward distribution: Incentives go to the right people – those who genuinely participated in the survey.
  • Data Integrity: Duplicate entries skew the survey results, making it look like certain options were way more popular than they actually were. This throws off your entire analysis and makes your survey basically pointless. Preventing duplicates ensures each response contributes uniquely to the dataset, preserving integrity.
  • Enhanced Trustworthiness: By stopping multiple submissions from the same source, ensuring the data collected from online panels is genuine. And help data collectors trust that the collected data is not farmed and gamed for incentives.

How to set it up in BlockSurvey?

BlockSurvey offers two ways to prevent duplicate submissions, depending on your needs:

  1. Browser-Level Prevention
  2. Question level Prevention

Browser-Level Prevention

This would be a good choice for general surveys where anonymity is okay. Set it up easy and quick in  BlockSurvey. Just toggle off the “Allow multiple submissions per user” option under Settings -> Response Management in a survey. By this, you can prevent users from submitting the survey more than once from the same browser.

Question level Prevention

For precise results BlockSurvey lets you verify the respondent’s identity at the question level by simply toggle on the “Prevent duplicate submission” option under the Options tab of Email, Contact form, Social, or Web 3 identity verification questions.

How does this work at the question level?

  • Email and Contact form: BlockSurvey looks for the email address if the same email address is used more than once it stops the user from submitting the survey.
  • Social identity verification: Connect and verify your social account (like TwitterDiscordGithubGoogle, and LinkedIn). If someone tries to submit the survey again using the same verified social media account, they'll be stopped from making the submission. This ensures only one response per verified social identity.
  • Web3 identity verification: Connect and verify your crypto wallet. If someone uses the same wallet address to submit the survey more than once, it won't work! This is great for surveys targeting specific crypto communities.

What is unique about BlockSurvey’s duplication prevention for Web 3 companies?

BlockSurvey offers a unique feature for Web3 companies: Prevent Duplicate Submission By NFT TokenID.

This is especially helpful when dealing with NFT-gated experiences or content. Thinking someone might just transfer their NFTs to another wallet to participate multiple times? BlockSurvey has that covered too! By verifying all the NFT TokenIds a user holds, prevents duplicate submissions even if the NFTs are transferred after the initial verification. This ensures fair and secure participation.

What are some use cases you should turn on Duplicate Prevention?

  • Event Registrations: When using email in the survey for event registrations or RSVPs, preventing duplicates ensures an accurate count of attendees and helps organizers plan effectively for the event.
  • Market Research via Social Media: Conducting market research surveys distributed through social media platforms like Twitter. Duplicate Prevention ensures that each user's response is unique, preventing individuals from skewing the results by submitting multiple responses.
  • DAOs and Community Feedback: DAOs and online communities often use NFTs to represent membership or voting rights. Duplicate Prevention by NFT TokenID ensures that each NFT holder can participate only once in voting or providing feedback, maintaining the fairness and integrity of decision-making processes within the community.
  • Token Airdrops: Projects often distribute tokens as rewards or incentives to community members. Duplicate Prevention using wallet addresses ensures that each participant receives rewards only once, preventing abuse or exploitation of airdrop programs by individuals attempting to claim multiple rewards.


In conclusion, No more wasting time cleaning up messy data, just clear insights you can actually use. Plus, BlockSurvey makes things smooth for everyone – users won't accidentally submit the same survey twice, and rewards go to the right people. Say goodbye to duplicates and hello to clean, unique data, and get awesome insights from your surveys, every time! That's the power of BlockSurvey's Prevent Duplicates Submission feature.

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blog author description

Wilson Bright

Wilson Bright is the co-founder of BlockSurvey. He is an avid crypto enthusiast, and his vision is to make BlockSurvey a go-to infrastructure for data collection with a focus on privacy and security.


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