How to find study participants with specific characteristics

Recruiting the right participants can make or break a research study. When you need responses from niche audiences - whether that’s marketing professionals, parents of teenagers, or people with specific medical conditions - generic sampling won't work. You need a precise way to source the right people for your research.

Online participant recruitment platforms can solve this problem. They let you set precise criteria for who can take part in your study, using screening tools that filter by demographics, background, health status, and many other attributes.

Where these platforms differ, though, is in how reliable those filters are - and whether the people you recruit match the criteria you set.

In this article, we explore best practices for verifying characteristics and compare the screening and filtering capabilities of two prominent platforms on the market. 

Best practices for verifying participant characteristics

Even with strong screening tools, you should build verification into your research design. Self-reported data has inherent limitations, and layered screening helps ensure you're working with genuine participants who truly match your criteria.

Screen for unlikely combinations

One effective verification method is screening for characteristics that shouldn't appear together. For instance, if you're recruiting marketing professionals, also screen out current students. Someone working full-time in a marketing role while simultaneously enrolled as a full-time student represents an unusual edge case that deserves closer examination.

Define your target audience clearly

Ambiguous definitions create room for misinterpretation. Rather than screening for "entrepreneurs," specify what that means in your research context. Do you need business owners with employees, or does freelance work count? Are you looking for active businesses generating revenue, or do side projects qualify?

Different people interpret professional labels differently. Someone might consider themselves a marketing professional because they manage social media for a friend's small business, while your research needs people with formal marketing roles at established companies. Clear definitions prevent these mismatches.

Use layered screening questions

Instead of relying on a single yes-or-no question, build in multiple questions that should align if someone genuinely fits your criteria. For example, if you're recruiting entrepreneurs, ask about current business activity, revenue generation, incorporation status, employment status, and decision-making authority.

Genuine entrepreneurs will provide consistent, aligned responses across these questions. Someone who claims entrepreneur status but also reports being a full-time employee with no incorporation and no revenue likely doesn't meet your research definition, even if they technically run a side project.

Cross-validate responses within your survey

Include questions throughout your survey that serve as consistency checks. If someone claims expertise in a field, later questions should reveal that knowledge naturally. If responses seem inconsistent with the claimed background, you have reason to examine that participant's data more carefully during analysis.

This doesn't mean treating participants as dishonest by default. In fact, when participants respond to screening questions based on their own understanding, they're behaving honestly. The limitation lies in self-reporting itself. People might interpret professional terms differently, apply varying thresholds to what counts as expertise, or understand questions in ways you didn't anticipate.

These verification strategies work best when supported by platforms that prioritize screening accuracy from the start. But which platform should you choose? Let’s look at the screening capabilities of two prominent platforms: Prolific and MTurk. 

Prolific: built-in screeners and custom screening tools

Prolific is designed specifically for researchers who need reliable, high-quality data. The platform offers two main ways to screen participants: 

• 300+ pre-screeners
• Custom screening questions 

Pre-built screeners

Prolific maintains a constantly updated database of participant attributes. When you create a study, you can use over 300 prescreeners to filter for characteristics like age, employment status, education level, income bracket, and health conditions.

Screener sets for recurring research needs

If you regularly recruit the same type of participants, Prolific's screener sets feature streamlines your workflow. Rather than manually applying the same combination of filters each time you launch a study, you can save commonly used prescreeners as a template.

For example, if your research frequently requires right-handed, bilingual participants aged 30 and above, you can create a screener set combining handedness, bilingual status, and age filters. The next time you need this exact combination, you simply select your saved screener set instead of rebuilding the criteria from scratch.

Custom screening questions

For more specialized research requirements, Prolific's custom screening feature lets you design your own questions to identify exactly the participants you need. While the built-in prescreeners cover common demographic criteria like age or political affiliation, custom screening helps you find participants with very specific characteristics that aren't covered by standard filters.

For instance, if you need participants who take omega-3 supplements, own electric vehicles, or use specific software tools, you can create custom screening questions to identify these unique demographics.

Custom screeners work as pre-survey questions. Prolific shows them to eligible participants before they enter your study, ensuring only those who match your requirements can take part. 

Audience Finder for hard-to-reach groups

When you need participants with rare or very specific characteristics, Prolific's Audience Finder can help. This tool connects you with specialized groups, including domain experts in fields like healthcare, finance, law, and engineering.

Audience Finder is particularly valuable when you're: 

• Recruiting professionals who need deep expertise in their field
• Conducting research that requires participants with rare conditions or experiences
• Building AI systems that need domain expert validation

Amazon Mechanical Turk: minimal screening capabilities

Amazon Mechanical Turk offers basic demographic filtering. However, the platform wasn't built with research quality as its primary goal. MTurk started as a marketplace for simple tasks, and that origin shows in how participant screening works.

Limited built-in filters

MTurk provides basic filters for location and approval rating. But it lacks the comprehensive demographic screening that research often requires. 

If you need participants with specific characteristics, you'll need to include screening questions in your survey itself. This limitation also means you can't effectively screen for unlikely combinations of characteristics. 

Quality concerns

MTurk has minimal verification processes for participant attributes. Studies have consistently shown issues with data quality on the platform, including: 

• Participants who misrepresent their characteristics to qualify for more studies
• People who use VPNs to bypass location restrictions
• Bot activity that goes undetected

These quality issues matter when your research depends on recruiting specific populations. For example, a study targeting healthcare professionals may inadvertently include people who claim that status to access more studies.

Finding the right platform for your research

Demographic screening tools only work as well as the verification processes behind them. Prolific prioritizes research quality with verified participant attributes, comprehensive screening options, and tools designed specifically for academic and commercial research needs.

When your research depends on recruiting the right people, the platform you choose shapes the quality of your data. Use Prolific's Audience Finder to connect with participants who match your criteria and deliver the reliable responses your research demands.