![Rooms without walls][1]
Different groups of children were asked to draw exactly what they saw in four configurations of a fort (Exp. 1, top) or toy (Exp. 2, bottom). Examples of children's drawings illustrate how children in the fort tended to leave out the walls.
[1]: https://files.osf.io/v1/resources/5wng2/providers/osfstorage/5d5630ed150734001dc4e915?mode=render