A series of hand-drawn QR codes, drawn freehand, using a large, black, felt-tip pen. The participant is not allowed to trace them or use a ruler or any other aid and must make every effort to get them right.
The code itself links to a page showing this description. It is a circular relationship, making it an entirely pointless exercise, apart from serving as a test of concentration and steady hand at that particular time (about an hour).
Sometimes it is successful, and can be scanned. Sometimes, when there is too much erring, it fails to scan.
It is a Voight-Kampff test in reverse, where the participant’s humanity is confirmed by failure rather than success.
Geraint Edwards, Reverse Voight-Kampff (Impossible Material catalogue cover), marker pen on paper (digitally coloured), 2017