In preparation for blind retrieves, Stewart's dogs run four memory exercises, including sight, trailing, circle, and loop drills. The dogs then learn "permanent unseens," "time-delay memories," and "cold unseens." In a permanent unseen the bumper is preplaced, so the dog has not seen it.
What is a cold blind?
A "cold blind," for those unfamiliar with the term, means that the dog has no idea of where the bird is--he didn't see it fall, its location is not part of a "pattern" he recognizes, nor is it at a location he's been to before (a "permanent" blind). ... A dog's trust, confidence and momentum can be damaged this way.