A group of children is defined by the number of children assigned to a specific caregiver or group of caregivers, occupying an individual classroom or well-defined physical space within a larger room. Each child in any group has two things in common with every other child in his group: the same caregiver(s) responsible for the child's basic needs and the same classroom or activity space. Generally, the group stays with the assigned caregiver(s) throughout the day and may move to different areas throughout the child-care center, indoors and out. The group may not mix freely with other children, unless specific criteria are met as specified in this subchapter. The number of children who may be in a group varies according to the age of the children and the number of caregivers as specified in this subchapter.