Discrimination in training is defined as:

• A. A response offered in the presence of the conditioned stimulus and presence of other stimuli
• B. A response offered only when the cue is absent
• C. A response offered after punishment
• D. A response offered in the presence of the conditioned stimulus and not in the presence of other stimuli

Answer: (D)

Discrimination in training means teaching the dog to respond to a specific cue while ignoring other stimuli. This is done with differential reinforcement: the correct behavior is rewarded when the cue is present, but no reward is given (and other cues are not reinforced) when different stimuli are present. Over time, the dog learns that the behavior is valuable only in the exact context of that cue, reducing responses to other, non-target stimuli. In contrast, if the dog responds to many similar cues or to cues without the target context, that indicates poor discrimination or generalization, which would require adjusting training to sharpen the distinction between signals.