Stimulus generalization is more likely to occur when:

Stimulus generalization refers to the tendency for the effects of a learning experience to extend to similar stimuli beyond those that were originally conditioned. When stimuli share more similar properties, the likelihood of generalization increases. This happens because the learner is more likely to recognize and respond to stimuli that possess characteristics similar to those of the conditioned stimulus.

For example, if a child has been conditioned to respond to a specific tone that was used during a learning task, they might also respond to other tones that share similar auditory properties, such as pitch or volume. The more alike the new stimuli are to the original stimuli in terms of features and context, the higher the chances that the learned response will be invoked.

In contrast, if stimuli share different properties, it is less probable that generalization will occur, as the learner may distinguish between them instead of associating them with the same response. Presenting stimuli in a random order might disrupt the association process and make it harder for generalization to take place. Likewise, direct omission of reinforcement may weaken associations and reduce the likelihood of generalization, as the learner may not maintain the response in the absence of reinforcement.