Pictorial representations of routes: Chunking route segments during comprehension

Route directions are usually conveyed either by graphical means, Le. by illustrating the route in a map or drawing a sketch-maps or, linguistically by giving spoken or written route instructions, or by combining both kinds of external representations. In most cases route directions are given in advance, i.e. prior to the actual traveling. But they may also be communicated quasisimultaneously to the movement along the route, for example, in the case of incar navigation systems. We dub this latter kind accompanying route directions. Accompanying route direction may be communicated in a dialogue, i.e. with hearer feedback, or, in a monologue, i.e. without hearer feedback. In this article we focus on accompanying route directions without hearer feedback. We start with theoretical considerations from spatial cognition research about the interaction between internal and external representations interconnecting linguistic aspects of verbal route directions with findings from cognitive psychology on route knowledge. In particular we are interested in whether speakers merge elementary route segments into higher order chunks in accompanying route directions. This process, which we identify as spatial chunking, is subsequently investigated in a case study. We have speakers produce accompanying route directions without hearer feedback on the basis of a route that is presented in a spatially veridical map. We vary presentation mode of the route: In the static mode the route in presented as a discrete line, in the dynamic mode, it is presented as a moving dot. Similarities across presentation modes suggest overall organization principles for route directions, which are both independent of the type of route direction-in advance versus accompanying-and of presentation mode-static versus dynamic. We conclude that spatial chunking is a robust and efficient conceptual process that is partly independent of preplanning.