This is Katy, one of InSitu's best cancer detection dogs. Handler and dog are doing a "single blind" run, where handler Dina Zaphiris does not know where the cancer sample is among the healthy samples. When Katy alerts at slot 5 (which is the cancer sample) Dina calls it out, and the experimenter tells her yes, that's correct. This is how we prevent giving subtle cues to the dog. When the handler knows where the cancer is, they may unconsciously give a subtle cue to the dog when approaching the cancer sample. Single blind runs proof the dogs and handlers as a team, making sure the dogs are doing their job with no extra help from the handler, once they are fully trained. Helping the dogs is good in the beginning, but a good handler has to let the dog work independently, always. Notice how all of these dogs first alert with their BACKS to the handler.