# Find Your Perfect Participants
Valid research starts by finding the right people to participate. We call this screening. Screening allows you to require participants to answer one or more questions that you specify to any level of granularity you like.
Our panel is big, consisting of millions of people in over 150 countries. It's so big and comprehensive, we have no problem letting you require up to 10 screening questions that participants must answer correctly to participate in your study.
In practice, most studies ask just one to three questions because most "targeting" can be boiled down to only a few questions. For example, if you're a credit card company, you want to ensure that people have a credit card.
# Screening basics
Writing a good screening question consists of a question and a list of answer choices. The question can either be a single or multi-select (multiple choice) style. And like all of our survey-style questions, you can choose from a list of pre-made questions or create your question from scratch.
Screening questions are created when you create your study. A screening question differs from a regular study question in one crucial respect. Each screening question item has a screen-out checkbox. Select this box if you want to screen out (not include) who selects this item.
Screening in action.
Formulating screening questions is how you get the participants you want. This shows an age screening question, where certain age ranges are screened out.
# Writing a good screening question
A good screening question usually consists of a list of choices that don't reveal the intent of the question. So, for example, consider the difference between a yes/no question like "Do you have a credit card?" and a question that asks "What financial products you currently have" which lists five to seven options, one of which is a credit card.
Structuring your questions this way can also help when presenting your results, because you've just minimized a natural reservation people will have.
# What if I don't want to screen?
You don't have to screen, and some projects do not require it since the market for the product is pretty much anyone. If you have a product like this, you'll be happy to know these studies are the least expensive and fastest to run.
When you don't ask a screening question in your study, we still ask three basic demographic questions about gender, age, and technology use, so you'll always have some information about who each participant is.
# The impact of screening on cost
As you probably can guess, the more screening questions you ask, the harder it is to find participants that match a given profile. The way we manage this is by increasing the incentive (the amount of money we pay the participant). The increased incentive improves the likelihood that people will try to qualify.
The simple formula is this: for every screening question you ask, we add an additional $5 onto the per-response charge. This allows us to pay the participant more and generally ensures your study will be a success.
# The impact of screening on study completion time
Because we increase the participant incentive, the more questions you ask, the impact of screening on study completion time is often negligible. Of course, it all depends on what you're screening for, and the number of participants, but generally most of our studies complete in a day or two, with longer times for larger samples.
# Screening and other demographic questions
Sometimes you want to collect information about who people are (their demographics), without screening. If this is the case, we generally recommend including the question in the body of the study itself (in the Study portion of our study creation process), rather than in the Screening section). That said, there is one exception to this: when you want to set specific quotas for participants, which is a feature is only available when you have screening questions.
# To screen or not to screen
A good test is this: if you want the question to affect the allocation of participants within the test, make it a screening question. If it doesn't matter to the allocation, and you want to know something about a participant, put it in the body of the study.