1You will see two intervals of flickering dots — one contains a slightly higher number of dots
2Decide which interval had more dots (left or right)
3After each decision, rate your confidence from 1 (guessing) to 4 (certain)
4There are no trick questions — follow your instinct and be honest about your confidence
What this measures
Meta-d' (meta-d prime) quantifies how efficiently a person uses their first-order perceptual sensitivity to generate accurate confidence judgements. A high meta-d'/d' ratio (Mratio) indicates well-calibrated metacognitive monitoring.