A Short-Term Set is a source for expectancies.
This amounts to giving a person an idea of what is coming next. For children it is an excellent teaching technique. It is particularly useful when a child is being taken on an expedition, like to the fire station.
Before the field trip takes place, some preparation can profitably be done.
Discussions (games, play acting, or stories) with pictures and/or if possible toys of fire stations, fire men and fire engines and many of l their tools would be good activities.
These would prepare the children by providing expectancies to facilitate the decoding of the sounds and sights they will experience during the visit.
Without the expectancies, they may be easily over stimulated and overwhelmed perceptually, and may shut down in many ways--become very tired, cranky, distractible, mischievous, withdrawn etc.