In the first exercise, the dog previously observes how the "victim" or helper climbs inside the box or chest. The point of where the dog is let of theis always the same place and the dog at this point can only see the box that is covered by a plastic top. The place where the dog is let off the should be close to the box, although at this point of the training the dog should not be able to see the box anymore. The trainer will need to wait behind a wall or a car for instance, and once the dog has found the "victim" and has started barking, the trainer will then go up to the dog and will praise and pat it. The box will then need to be partially covered with debris and the trainer will need to control how much or how little it should be covered so as to help the dog with the next phase of the training. The trainer needs to keep in mind that the dog may become inhibited by the amount of debris on top of the box; therefore he or she will have to measure the amount the dog can take.
These steps should be taken progressively until the dog is able to get to the point of signaling by barking with full assuredness when it has found the person inside the box that is inside the box covered completely by debris. The signaling phase will be complete once the dog is able to fully do this exercise in a new unknown place. This is a good way to tell if the debris on top of the box caused sufficient predictive stimulus to the dog. The debris that will need to be used on the second box should not be the same ones that were used for the first stage, although they should obviously offer the dog some similar basic traces. One very important and fundamental aspect to keep in mind when doing and preparing these exercises is to always take into account that the dog will need to be the one that lifts the debris off of the box. Because of this, it is important that you are careful with the weight of the debris and you will need to have the dog practice opening the box before hand too. Remember also that when these types of exercises are done it is important to simulate them to the real thing as much as possible. This means that all the people and the dog will need to be wearing all the security accessories such as a safety helmet etc depending on the case.
During the developing phase of the signaling, make sure to always apply or use, depending on what is necessary the following techniques: Progressive autonomy by action of the mannequin effect. Innocuous reestablishment by applying sounds.