Referral Terms

1. Eligibility

Open to completed Spot the Fake study sessions whose participants are aged 18 or over.
A completed participant may activate one referral profile for their current anonymous browser session.
Members of the research team, their immediate families, and direct associates are excluded.
Clearing cookies or changing devices loses access; the organisers do not use fingerprinting or stronger identity collection to reconnect sessions.

Only direct referrals using the participant's three-word link count.
The first valid referral link visited before a new participant starts the study is retained.
A referral counts only after the referred session completes every assigned case.
Each completed study session can credit no more than one referrer.
Self-referrals within the same anonymous session are excluded.
Referral credits are not backfilled for earlier completed sessions.

The challenge is available only while the organisers keep it active.
The closing time is August 11, 2026, at 23:59 BST.
The final study judgment must be recorded before closing. A 30-minute settlement period allows already-recorded completions to finish processing.
No new links or credits are accepted after the applicable deadline.

The prize is one £50 Amazon voucher.
The participant with the most valid completed direct referrals wins.
Ties are resolved by the earliest time the final referral count was reached, then the earliest profile activation time, then random choice.
At least one valid completed referral is required to win.
The prize is non-exchangeable, non-transferable, and no cash alternative is offered.
Participants see only their own count and rank. A participant who is not leading sees how many completed referrals they need to lead; the leader sees how many the closest participant needs to overtake them. No competitor names, codes, or individual counts are shown.
The organisers' decision on eligibility, valid referral credits, ranking, and prize administration is final, subject to applicable law.

The winner will be notified via their separate referral contact email within 7 days after settlement.
The winner must reply within 14 days to claim the prize.
If the winner does not respond, the next-ranked eligible participant will be contacted.

Referral data are stored separately from study responses and the £100 prize draw.
The system stores a campaign-specific pseudonym, three-word code, completed credits, and referral contact email; it stores no raw study IDs or response keys.
The pseudonym is recomputable by an authorised operator holding a separate secret and is therefore pseudonymised, not fully anonymous.
Contact emails are deleted after prize verification. Participant-level referral records are deleted after the 30-day dispute window.
Referral information is used only to administer the referral challenge.

This challenge is organised by Konstantin Sturtzkopf (kcs41@cam.ac.uk) and Dr. Miri Zilka as part of a University of Cambridge study on human perception of generative media.