Most training and learning, indeed any acquired skill, occurs in a series of steps or approximations. This is true regardless of the technique or type of learning that is taking place. So for example, in scan and capture the trainer is looking for the smallest unit of behavior that leads from where the animal currently is to one unit closer to the behavior you are looking for. In baiting, this would be using some form of draw to lure the animal a step closer to your goal and in negative reinforcement it would be to teach the animal to yield to the smallest unit of pressure in the right direction of the goal behavior. Much depends on the sensitivity of the trainer to choose the appropriate size or unit of approximation and to decide expertly when to move forward and when to repeat and rehearse. If fear is a component of the equation, then the trainer should opt for more rehearsals at the same approximation until smooth and eager behavior is demonstrated which indicates the readiness to move on.