Scale has been a defining criterion of mapmaking for centuries. However, this criterion is fundamentally questioned by highly immersive virtual reality (VR) systems able to represent geographic environments at a high level of detail and, thus, providing the user with a feeling of being present in VR space. In this paper, we will use the concept of scale as a vehicle for discussing some of the main differences between immersive VR and non-immersive geovisualization products. Based on a short review of diverging meanings of scale we will propose possible approaches to the issue of both spatial and temporal scale in immersive VR. Our considerations shall encourage a more detailed treatment of the specific characteristics of immersive geovisualization to facilitate deeper conceptual integration of immersive and non-immersive visualization in the realm of cartography.

Abstract. Needs and preferences in wayfinding tasks of people with autism spectrum disorders (ASD) have been a topic of ongoing discussion in the scientific literature over the last decades. While different tasks have revealed both autistic strengths (e.g., encoding and recall of route information) and weaknesses (e.g., understanding allocentric representations), ASD spatial behaviour is not fully understood yet. In this paper we focus on spatial uncertainty, which is the discrepancy between a-priori expectation and in-situ experience and thus a constant factor in ASD wayfinding tasks. As a matter of course, spatial uncertainty is inevitable, always resulting from a dynamic interaction of situational qualities (e.g., noise or smell). Nevertheless, mapping uncertainty and the underlying spatial patterns in an organized way might help users from the ASD spectrum to better prepare for the different levels of expectable uncertainty in route. We propose a framework of conceptualizing, measuring, and mapping spatial uncertainty from an autistic viewpoint. The discussion of this framework is based on a qualitative analysis of the spatial behaviour of B, a five-year-old child with ASD and nonverbal communication, in an urban environment. We compare the level of spatial uncertainty of the routes developed by B against the routes indicated by ourselves.