Geographic Event Conceptualization: Where Spatial and Cognitive Sciences Meet

Geographic Event Conceptualization: Where Spatial and Cognitive Sciences Meet Rui Li, Alexander Klippel, Jinlong Yang {rui.li, klippel, jinlong}@psu.edu GeoVISTA Center, Department of Geography 302 Walker Building, The Pennsylvania State University, University Park, PA 16802 USA Abstract We present the results of two behavioral experiments on the conceptualization of geographic events (here, the movements of hurricanes). The focus is on juxtaposing two types of presentation: static versus animated trajectories. We designed 72 animated and 72 static icons of the same hurricane movements and asked participants to group them. Within each condition we distinguished paths of hurricanes using topological equivalence classes. Topology allows for differentiating ending relations that are potentially relevant for event conceptualization (Regier, 2007). Results show that motion matters. Participants constructed static icon groups more distinctly and focused more on ending relations. The presentation mode additionally influenced linguistic descriptions. These findings contribute to understanding and formalizing geographic event conceptualization. Keywords: Category construction; geographic event conceptualization; topological relations; movement patterns. Introduction Event cognition is addressed in several research fields and as such, this article caters to an interdisciplinary community. Cognitive scientists address questions of event segmentation (Zacks, et al., 2001), the role of causal relationships (Wolff, 2008), or how events are related to language (Talmy, 1988); spatial scientists are interested in formally characterizing movement patterns (Gottfried, analyzing spatio-temporal information (Yuan & Hornsby, 2008), and more recently, using formal characterization to ground the semantics of movement patterns by formally capturing those aspects of movement patterns which are meaningful to a cognitive agent (Kurata & Egenhofer, 2009). Topology, as one aspect of the spatial characterization of events, has long been a topic of interest to both spatial science and cognitive science communities. This article uses a topological framework to provide a formalized understanding of geographic event conceptualization, and discusses topology from a multidisciplinary perspective. The importance of topology is based on two main aspects. First, topological characterizations are qualitative and offer an abstract-level characterization of spatial information, which is potentially relevant to higher-level cognition, as knowledge is created through abstraction. Second, topology offers a formal basis for identifying invariants in spatial information. These invariants might be the very basis of event cognition. One critical aspect in event cognition is coherence, which allows for the determination of meaningful units/segments of events (Tversky, et al., 2008). Identifying topologically equivalent events (or parts thereof) may therefore contribute to rendering the notion of coherence more precise. In this article we focus on geographic events and more specifically on the paths of hurricane movements. From a formal, topological perspective, path characteristics can be captured using either of the two most prominent topological frameworks in spatial information science, the region connection calculus, RCC (Randell, et al., 1992), or Egenhofer’s intersection models (Egenhofer & Franzosa, 1991). An assumption we need to make is that both entities (figure or moving entity, and ground or reference entity) are spatially extended (see Figure 1). The central question that we address here is whether the mode of presentation (dynamic or static) results in different conceptualizations of this geographic event. This question has been addressed in multidisciplinary search efforts; for example, Tversky and collaborators (2002) questioned whether animation facilitates learning and information processing; Gentner and Boroditsky (2001) found that learning verbs poses more difficulties than learning names of objects; and, closely related to our research here, Maguire and collaborators (in press) found that geometric path characteristics are used differently to segment events depending on the presentation mode (static or dynamic). To operationalize this research question from a topological perspective, we employ a modification of the endpoint hypothesis (Regier, 1996; Regier & Zheng, 2007). The essence of this hypothesis states that a focus (by a cognitive agent) is placed on ending relations in processing spatio-temporal information. Within the framework of topological characterization, ending relations of events can be formally characterized by different topological relations (as identified by the RCC or intersection models). Here we focus exclusively on topological relations and the mode of presentation while excluding other aspects such as shape or speed changes. Our goal is to use a multi-methodological, formally grounded