@cstross Agreed. I've never seen it well defined, it's always just "does it fool you personally for 15 minutes". Eliza did that to people in the 1970s. The Sims did it here:
https://aliceandkev.wordpress.com/
People assume there are professional Turing testers, a man with a clipboard somewhere who's an expert at testing turings and you can phone them up to make an appointment. Meanwhile, humans see faces in clouds, put googly eyes on the roomba, ask their car out loud to start on cold mornings...