Pii: S0010-0277(99)00038-4

Spatial prepositions such as in and on seem to denote semantically indeterminate spatial relations. This re ̄ects, in part, the physical relationships between the objects in the scenes that they are used to portray. We argue that such physical relationships are best represented in terms of an inherently dynamic functional geometry which incorporates notions of location control. Two experiments are reported. They investigate the degree to which independent judgements of location control predict choice of description across a range of scenes. The results show that judgements of location control predict viewer's choice of description under certain circumstances. In the absence of prototypical geometric relations, control information has a strong in ̄uence on choice of description. However, when the scenes portray prototypical geometric relations, control information has less of an effect. The results support a hybrid account of the semantic representation underlying the prepositions with both a geometric and a functional component to it. q 1999 Elsevier Science B.V. All rights reserved.