Final answer:
The key factor in determining if an observer repeats a model's behavior is the consequences the model experiences, which influence the observer's motivation.
Step-by-step explanation:
The factor that is important in determining whether an observer repeats the behavior of a model is consequences. This fits within the context of the modeling process whereby the steps include attention, retention, reproduction, and motivation. The observer needs to be motivated to repeat the behavior, and this motivation is impacted by the consequences the model faces. If positive reinforcement is observed (vicarious reinforcement), the observer is more likely to replicate the behavior. Conversely, if the model is punished (vicarious punishment), the observer is less likely to repeat it.