⚠️ We’re about to launch an upgrade to our custom screening, which gives you better control over how much you spend. This feature will be available directly within Prolific and via the API, coming soon!

Contents:

This article will explain how to recruit the exact participants you need for your study using Prolific’s custom screening feature.

1. What is custom screening?
2. Recommended format
4. Two-study screening approach
3. Cost/Rewards
5. Setting up your survey using the custom screening feature
6. Managing submissions

What is custom screening?

Custom screening lets you check for participant characteristics that aren't available in our built-in prescreening options.

While our free built-in prescreeners cover common criteria (like being right-handed), you might need participants with very specific traits that we don't screen for. For instance, if you need participants who have an uncle named Jim, you'd use custom screening to identify this unique demographic.

It’s important to note that custom screening can’t be used alongside our representative samples.

If custom screening isn’t what you’re looking for, you also may find our articles on ‘built-in prescreening’ and ‘validating prescreening’ helpful.

Recommended formatting

When it comes to recruiting a custom sample, we recommend keeping your screening questions vague so that participants are not influenced to answer a certain way. We recommend setting up your study to only allow one response per participant to ensure your participant pool is accurate. Make sure to configure your external software to do the same.

One method is to ask a variety of questions so that the participants don't know which one you're actually measuring. You could, for example, ask the following questions with 'yes/no' answer options:

  • "I do open water swimming at least twice a month"
  • "I own an Air BnB"
  • "I use an electric toothbrush"
  • "I use an Uber at least twice a week"
  • "I own a poodle"
  • "I have 3 children"

Your custom screening questions should be set as mandatory/required responses (if your external survey software offers this feature) and should appear at the very beginning of the study. This ensures participants who don't meet your criteria are screened out immediately.

Finally, we also encourage keeping the title of your study ambiguous to prevent participants from being influenced in their answers.

This formatting approach is recommended for all screening methods described below.

Two-study screening approach

⚠️ Important note: While we're rolling out our new custom screening feature within Prolific, we recommend using the two-study screening approach described above. This tried-and-tested method ensures you can still effectively custom-screen participants until the enhanced in-platform functionality becomes available to all researchers.

If you’re unable to obtain the specific population you require using our existing prescreening filters, you can run two separate studies on Prolific to recruit your sample.

When budgeting for the two-study approach, it's important to consider that you'll need to account for both the screening study payments (minimum £0.10/$0.14 per participant) and the full reward for those who qualify for and complete the main study. To help with planning: let’s say you're aiming to find 100 eligible participants, you may need to screen a larger pool of participants first to reach your target sample size.

Step 1: Create Initial Screening Study

  • Set up a simple screening survey. If you’re located in the UK, EEA, Canada, New Zealand, Japan, Israel, Argentina, South Korea, or the USA, we recommend using our in-built Survey builder; otherwise, checkout out our integration guides for an alternative external survey software. It’s also important to note our Survey builder is not suitable for sensitive questions.
    • First, add your screening question following the recommended formatting above (e.g., "I have an uncle named Jim")
    • Then, include basic response options (e.g., Yes/No)
    • Next, you’ll set your sample size (e.g., 20 participants)

Step 2: Collect and Review Responses

  • Publish your screening study
    • Once the correct number of participants have completed the survey, review the responses to identify eligible participants
      • If you used external survey software, your data will be stored there
      • If you used Prolific's Survey Builder, your data will be stored on Prolific

Step 3: Set Up Main Study

  • Create a new study that contains your main research content, including all your survey questions, tasks, or other research materials. This will be the full version of your study that qualified participants will complete after passing the screening criteria
  • Add the ‘Custom Allowlist’ screener or participant group
  • Paste in the Prolific IDs of eligible participants from the screening study

There is no reason to apply a blocklist when publishing your main study as it will only be visible to the participants you've specifically allowed through the ‘Custom Allowlist’.

✋ Please note: The information below pertains to an upcoming custom screening feature within Prolific that is not yet available.

Custom screening update coming soon

Cost/rewards

With our new version of custom screening, we've simplified how participants are rewarded:

Fixed rewards instead of an hourly rate

When using custom screening, you'll need to set a fixed reward for screened-out participants. This amount must be at least £0.10 or $0.14, but cannot exceed the full study reward that participants who complete the entire study will receive. It's important to note that once your study has been published, this screen-out reward cannot be adjusted.

See total screening costs upfront

We've streamlined the accounting process for screen-out rewards. While these payments are still processed as bonuses, they're now included in your upfront study costs instead of affecting your wallet's remaining balance separately. This means you'll see these potential expenses clearly reflected in the estimated costs for these studies.

Automatic payment and refund process

Screened out participants will be automatically paid the fixed amount for completing screening. If your study completes without using all the screen-out slots you budgeted for (because all study places were successfully filled with qualifying participants), any unused amount that was initially charged to cover potentially screened-out participants will be automatically returned to your account when the study is completed.

Limit the number of screen-out slots to stay within budget.

You can specify the maximum number of participants who can be screened out of your study. Once this limit is reached, your study will automatically pause to prevent unexpected costs. You'll receive an email notification when this happens, allowing you to either increase your screen-out slots with additional budget or leave the study paused.

Setting up your survey using the custom screening feature

Step 1: Create your screening survey

First, head over to your preferred external survey software and create something new. If you need some help, our integration guides have specific instructions for the most common survey software.

Next, add your prescreening questions at the beginning of your study (scroll up to see our recommended formatting) - remember to keep them vague so that participants aren’t influenced to answer a certain way.

Next, you'll want to set up your survey to take different paths:

  • If someone answers "Yes" they'll continue to your main survey
  • If it's a "No" they'll be directed to your end of survey message

Again, check out our integration guides for how to set up these paths, including how to create your end of survey message in your software.

Step 2: Move over to Prolific

  • Under Data Collection type, select ‘External Study Link’
  • Once you’ve filled in all the relevant study details head to the ‘Data collection’ section.
  • Pop in your survey link, then scroll down to ‘Custom screening’ and enable it by clicking ‘Yes’. Custom screening won't be available until you've completed these two steps.

Step 3: Setting up custom screening

When setting up your study on Prolific, you'll need to configure how participants who don't qualify will be handled:

Input the number of screen-out slots:

You'll need to specify the maximum number of participants that can be screened out. This is separate from your study's total number of places. Once the maximum screen-out slots are filled, your study automatically pauses.

Input the screen-out reward amount:

Set a fixed payment for screened-out participants (minimum £0.10/$0.14). This reward cannot be changed after publishing your study.

Automatic handling

Once a participant is screened-out they’re now automatically approved and paid. Participants receive the "SCREENED OUT" which means you no longer have to manually select each participant and mark them as screened out.

Cost transparency

The study setup page shows a detailed cost breakdown, allowing you to see the cost of your screen-out slots and rewards, all of which are included in your total study budget.

Managing screened-out submissions

In the new version of custom screening, the process of managing screened-out participants has been streamlined to save you time and provide greater transparency.

Automated screening process

The system now handles most screening automatically. You'll no longer be prompted to manually enter payment amounts for screened-out participants, as the fixed reward you set during study creation is automatically applied. This reward remains constant regardless of how long participants spent on the screening questions.

Screen out slots vs. study places

Screen-out slots = the number of participants you’re happy to screen out and pay.

Study places = the total number of participants you need to pass custom screening and take the study.

Screened-out submissions now use dedicated "slots" on top of study places. This means you don't need to worry about reopening places when participants are screened out. If all your screen-out slots become filled, your study will automatically pause to prevent unexpected costs. You can then choose to increase the number of slots if needed.

Enhanced visibility

The updated study page provides clear visibility into your screening process. You can easily monitor your slot usage and view detailed information about automatically screened-out submissions in the dedicated "Screened-out" tab. This makes it simple to track how many participants have been screened out and why.

Adding more slots

If you need additional screening capacity, a new action allows you to increase your study's slots. When selected, a pop-up window will display the updated cost calculation for your study with the additional slots. Just like when increasing study places, you'll need sufficient funds in your wallet to cover these potential costs.

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