At Prolific, building a high quality pool of participants to take part in world-leading research is one of our biggest priorities. We are keen to grow this pool in as balanced a way as possible, to discourage population biases and maximise diversity.

For this reason we have decided to phase out our participant referral scheme over the next 3 months. This is a decision we have carefully considered as a team. Analyses performed by our research team indicate that participant referrals can cause problems by reinforcing certain demographics in our participant pool – a tendency we would like to curb in order to improve the diversity of our pool.

This change has some upsides for both researchers and participants: It will allow us to distribute studies across our pool more evenly. This should mean that fewer participants will find it hard to get any studies.

For those of you who have embedded referral links in your blogs or websites: We understand that you may be in the process of making referrals, so we're making sure to give you some time to adjust to this change. We will not be turning off this scheme straight away, and will instead disable new referrals 30 days from now (as of 13/02/19).

Here are the full details about how existing referrals will be affected:

New participant referrals can be made for up to 30 days from now (until 14th March 2019). After this date (14th March 2019), no new referrals can be made. We will honour existing referrals for up to 90 days from now, so referral rewards will be credited until 12th May 2019. After this date (12th May 2019), we will no longer honour any participant referrals.

Note: Our researcher referral scheme is unaffected by this change.

We appreciate the contribution that you, our participants, have made by referring your family, friends, and colleagues to Prolific – thank you for helping us spread the love! ♥️ We hope that you can understand this decision, and we are confident that this change will benefit you by offering existing users more studies, and an improved user experience. Stay tuned for further updates!