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This paper argues for the use of conceptual spaces in qualitative spatial and temporal reasoning. Conceptual spaces provide a natural framework for enriching the purely combinatorial and symbolic calculi such as Allen's calculus with a geometrical or topological structure. Recent work has shown that such enrichments are useful, since they provide simpler ways of characterizing tractable subclasses of the calculi. Hence part of the computational properties can be related to geometrical properties. The paper discusses a family of calculi (including Allen's calculus) for which substantial results have been obtained using this approach. It then examines other instances of calculi where the relationship has not yet been fully investigated and lists the main open questions which arise in this context. [ABSTRACT FROM AUTHOR]

For visual information processing, the derivation of meaningful low-level spatio-temporal information is challenging. In line with human visualisation and perception in spatial problem-solving, we believe explicit representations hold promise for efficient low-level abstractions. An approach for mapping spatial objects and relations, exploring diagrams' representation power for problem visualisation, is presented. Combined, qualitative spatio-temporal reasoning and diagrammatic reasoning directly influence information visualisation and abstraction over the physical substrate of a problem. The framework preserves objects' low-level spatio-temporal information over time, facilitating the interpretation of unique relationships. A 78% average activity recognition accuracy on the CAVIAR and Mind's Eye datasets demonstrates the effectiveness of the suggested abstraction approach. [ABSTRACT FROM AUTHOR]

Preferences in temporal problems are common but significant in many real world applications. In this paper, we extend our temporal reasoning framework, managing numeric and symbolic information, in order to handle preferences. Unlike the existing models managing single temporal preferences, ours supports four types of preferences, namely: numeric and symbolic temporal preferences, composite preferences and conditional preferences. This offers more expressive power in representing a wide variety of temporal constraint problems. The preferences are considered here as a set of soft constraints using a c-semiring structure with combination and projection operators. Solving temporal constraint problems with preferences consists in finding a solution satisfying all the temporal constraints while optimizing the preference values. This is handled by a variant of the branch and bound algorithm, we propose in this paper, and where constraint propagation is used to improve the time efficiency. Experimental tests, we conducted on randomly generated temporal constraint problems with preferences, favor a variant of MAC as the constraint propagation strategy that should be used within the branch and bound algorithm. [ABSTRACT FROM AUTHOR]

Manipulation planning is a complex task for robots with a manipulator arm that need to grasp objects in the environment, specifically under narrow spatial conditions restricting the workspace of the robot. A popular approach for generating motion plans is probabilistic roadmap planning. However, the sampling strategy of such planners is usually unguided, and hence may lead to motion plans that seem counterintuitive for a human observer. In this article we present an approach that generates heuristics for the probabilistic sampling strategy from spatial plans that abstract from concrete metric data. These spatial plans describe a free trajectory in the workspace of the robot on a purely qualitative level, i.e., by employing spatial relations from formalisms considered in the domain of Qualitative Spatial and Temporal Reasoning. We discuss how such formalisms and constraint-based reasoning methods can be applied to approximate geometrically feasible motions. The paper is completed by an evaluation of a hybrid planning system in different spatial settings showing that run-times are notably improved when an abstract plan is considered as a guidance heuristic. [ABSTRACT FROM AUTHOR]

Christian Freksa, a prominent figure in the fields of cognitive science and artificial intelligence, passed away suddenly on November 12, 2020. He had a long and multifaceted career, making substantial contributions to various research areas. Freksa's work focused on representing and utilizing incomplete and imprecise knowledge, as well as spatial and temporal knowledge. He played a crucial role in establishing the field of spatial cognition and was involved in numerous projects and conferences that advanced the understanding of this topic. Freksa was also known for his mentoring and leadership skills, leaving a lasting impact on his students and colleagues. [Extracted from the article]

Humans can learn spatial information through navigation in the environment. The nature of these spatial representations is constantly debated, including whether they conform to Euclidean geometry. The present study examined the types of Euclidean representations people may form while learning virtual wormhole mazes. Participants explored Euclidean or non-Euclidean tunnel mazes and drew maps of the landmark layout on a 2D canvas. The results showed that people have different, consistent strategies, some mainly preserving distance information while others mainly preserving turning angles. The straightness of the segments was mostly preserved. These results suggest that representations of non-Euclidean space may be highly variable across individuals, and possible Euclidean solutions need to be carefully examined before testing Euclidean vs alternative models. [ABSTRACT FROM AUTHOR]

Spatial language incorporates descriptions of locations, routes, and landscapes, and is used by humans daily. Research has addressed a wide range of aspects of spatial language, including its form; the ways in which it is selected and applied; and cognitive, geometric, and functional factors affecting its use. Furthermore, much work has been done on the automation of spatial language extraction, analysis, interpretation, and generation. To introduce the Special Issue on this broad topic, this paper reviews spatial language research framed by an extension to the well-known semantic triangle, the "spatial semantic pyramid," which represents both human spatial language and relevant computational research. By introducing it, we hope to stimulate discussion about gaps and future directions in this important research field. [ABSTRACT FROM AUTHOR]

We investigate means to automatically interpret natural language place descriptions, i.e., to relate all nouns in the input text that represent geographic entities to corresponding entities in a geographic database. This task is often referred to as geo-referencing. Automated methods can contribute to text-based human-machine interaction with geographic information systems (GIS) and enable volunteered geographic information (VGI) to be obtained from natural language descriptions. This paper is aimed to investigate the contribution of reasoning. We propose a set of spatial and ontological reasoning steps that help resolve ambiguous interpretationsin particular, regarding the interpretation of unnamed entities (a park, a river, etc.). By evaluating the method on a corpus of place descriptions, we show that incorporating reasoning techniques improves the performance of interpreting place descriptions. [ABSTRACT FROM AUTHOR]

In this paper we study the computational complexity of Fuzzy Qualitative Temporal Algebra (QAfuz), a framework that combines qualitative temporal constraints between points and intervals, and allows modelling vagueness and uncertainty. Its tractable fragments can be identified by generalizing the results obtained for crisp Constraint Satisfaction Problems (CSPs) to fuzzy CSPs (FCSPs); to do this, we apply a general methodology based on the notion of α-cut. In particular, the results concerning the tractability of Qualitative Algebra QA, obtained in a recent study by different authors, can be extended to identify the tractable algebras of the fuzzy Qualitative Algebra QAfuz in such a way that the obtained set is maximal, namely any maximal tractable fuzzy algebra belongs to this set. [ABSTRACT FROM AUTHOR]

Navigation systems have become increasingly available and more complex over the past few decades as maps have changed from largely static visual and paper-based representations to interactive and multimodal computerized systems. In this introductory article to the Special Issue on Human-computer Interaction, Geographic Information, and Navigation, we review literature across a variety of fields to generate nine design principles to guide future research and development of navigation systems. Specifically, we suggest making mobile navigation systems more accessible and multimodal, which will make the systems more inclusive and usable for all types of users. We also introduce the research articles contributed to the present special issue and suggest future research directions to empirically evaluate emerging and untested features of user-adapted and context-aware mobile navigation systems. [ABSTRACT FROM AUTHOR]

Reorientation depends greatly on the perceived geometric information, which constantly changes during navigation in urban environments. Environmental novelty, as a driver of exploratory behavior, is likely to engender this spatial Aha! moment. The paper investigates the contribution of two qualitatively different types of novelty, corresponding to distinct visuospatial cues: (a) situations that cause surprise, e.g., a sudden change in spaciousness; versus (b) situations that engender mystery, e.g., a change in the complexity of visuospatial information and the promise of gaining new information. Visibility graph analysis is used to quantify and examine these hypotheses in relation to participants' exploratory behavior and brain dynamics (EEG) during virtual navigation. The findings suggest that reorientation is a spatial boundary effect, associated primarily with a change in visuospatial complexity. [ABSTRACT FROM AUTHOR]

Navigation is an essential ability for mobile agents to be completely autonomous and able to perform complex actions. However, the problem of navigation for agents with limited (or no) perception of the world, or devoid of a fully defined motion model, has received little attention from research in AI and Robotics. One way to tackle this problem is to use guided navigation, in which other autonomous agents, endowed with perception, can combine their distinct viewpoints to infer the localization and the appropriate commands to guide a sensory deprived agent through a particular path. Due to the limited knowledge about the physical and perceptual characteristics of the guided agent, this task should be conducted on a level of abstraction allowing the use of a generic motion model, and high-level commands, that can be applied by any type of autonomous agents, including humans. The main task considered in this work is, given a group of autonomous agents perceiving their common environment with their independent, egocentric and local vision sensors, the development and evaluation of algorithms capable of producing a set of high-level commands (involving qualitative directions: e.g. move left, go straight ahead) capable of guiding a sensory deprived robot to a goal location. In order to accomplish this, the present paper assumes relations from the qualitative spatial reasoning formalism called StarVars, whose inference method is also used to build a model of the domain. This paper presents two qualitative-probabilistic algorithms for guided navigation using a particle filter and qualitative spatial relations. In the first algorithm, the particle filter is run upon a qualitative representation of the domain, whereas the second algorithm transforms the numerical output of a standard particle filter into qualitative relations to guide a sensory deprived robot. The proposed methods were evaluated with experiments carried out on a 2D humanoid robot simulator. A proof of concept executing the algorithms on a group of real humanoid robots is also presented. The results obtained demonstrate the success of the guided navigation models proposed in this work. [ABSTRACT FROM AUTHOR]

This study aimed to understand whether or not computer models of saliency could explain landmark saliency. An online survey was conducted and participants were asked to watch videos from a spatial navigation video game (Sea Hero Quest). Participants were asked to pay attention to the environments within which the boat was moving and to rate the perceived saliency of each landmark. In addition, state-of-the-art computer saliency models were used to objectively quantify landmark saliency. No significant relationship was found between objective and subjective saliency measures. This indicates that during passive observation of an environment while being navigated, current automated models of saliency fail to predict subjective reports of visual attention to landmarks. [ABSTRACT FROM AUTHOR]

Nearness expressions such as "near" are context-dependent spatial relations and are subject to the context variability effect. Depending on the provided context, "near" has a different semantic extension. We perform a literature review to identify the effect of context on "near". To integrate the insights from different disciplines, we apply Turney's contextualization framework which distinguishes between two types of features: primary and contextual. Primary features are the qualitative and quantitative distance measures and contextual features are the context factors used to determine a threshold on the nearness measurements. Additionally, we identify the appropriate features for different spatial tasks discussed in the literature. By doing so, we seek to build a foundation for a context-dependent model for "near". [ABSTRACT FROM AUTHOR]

Current Geographic Information Systems (gis) lack, to a large extent, support for spatial searches in which a user wants to find a configuration of objects described in qualitative terms. At the database level, these searches can be supported by providing new spatial operators that can capture the semantics of the qualitative spatial relations used in the description and by developing resolution strategies tailored for queries including these operators. We suggest a technical approach to include an open number of qualitative spatial relations ingisand discuss a processing workflow leading from a qualitative spatial description to a database query and to the search result. We present and empirically evaluate a resolution strategy for these queries that is based on hypergraph matching and that exploits their semantic and structural characteristics. Finally, we envision some realizations of these searches and discuss challenges that relate to the cognitive aspect. [ABSTRACT FROM PUBLISHER]

When searching for people in collapsed buildings, Urban Search and Rescue workers need to comprehend a complex cluttered scene observed through an endoscope under time pressure. This article addresses the effects of time pressure and spatial ability on the comprehension of a film showing a mock-up collapsed room that was explored using endoscope-like technology. Participants' task was to find the objects that were hidden in the rubble, describe where they had found them, and draw the scene. Analysis focused on coherence and spatial specificity. Results indicate that spatial skills were most decisive for understanding and conceptually integrating the scene. Time pressure only affected the amount of objects found, not the degree of conceptual integration as reflected in the descriptions. [ABSTRACT FROM AUTHOR]

We investigate the relation between nontrivial spatial concepts such as holes and string loops from a qualitative spatial reasoning perspective. In particular, we concentrate on a family of puzzles dealing with this kind of objects and explain how a loop formed in a string shows a similar behavior to a hole in an object, at least regarding the qualitative constraints it imposes on the solution of the puzzle. Unlike regular holes, however, we describe how string loops can be dynamically created and destroyed depending on the actions on the string. Furthermore, under a Knowledge Representation point of view, we provide a formalization that allows the different puzzle states to be described in terms of string crossings and loops, together with the actions that can be executed for a state transition and the complex effects they cause on the state representation. This implies the consideration of a formal representation of the side effects of actions that create or destroy string loops and the soundness of this representation with respect to the more general representation of string states in knot theory. [ABSTRACT FROM PUBLISHER]

People use verbal descriptions to communicate spatial information, externalising relevant parts of their mental spatial representations. In many situations, such as emergency response, the ability of a machine to interpret these verbal descriptions could assist in human-machine interaction. As a first step in such an endeavor, this paper presents an automatic approach that translates spatial objects and their spatial relations extracted from verbal descriptions via natural language processing into a plausible sketch map. The proposed methodology applies a hierarchical and dynamic sketch map drawing strategy that is inspired by heuristics people apply in their interpretation of place descriptions, in order to accommodate underspecifying, flexible and conflicting common language. The methodology is implemented and tested. This article ends with some insights for further research towards automatic interpretation of verbal place descriptions. [ABSTRACT FROM PUBLISHER]

This article introduces three papers in a special issue that considers new directions relating to spatio-temporal theories for environmental, urban, and social questions. This work gives an overview of some recent perspectives on temporal GIS research including for example, cognition of geospatial dynamics, challenges of big data for urban and environmental sciences, representing mobility, and new ideas about time and space-time in geographic information science among others. The three papers consider topics including space-time pattern analysis and information retrieval, human mobility patterns and urban dynamics from mobile phone data, and spatio-temporal change as it is relates to administrative boundaries. [ABSTRACT FROM PUBLISHER]

When the web became popular, people had to develop ways to talk and think about it. In the mid-1990s, we analyzed spatial language in “web talk.” We found that people described pages as places, and search as motion, both passive and active motion. Here we investigate web talk nearly two decades later. Our analysis reveals that some spatial language has stayed the same, and some has changed. Of special interest is how far fewer motion verbs are used nowadays. We argue that people naturally produce spatial metaphors when talking about new technological domains, and that over time, the most useful elements persist. [ABSTRACT FROM PUBLISHER]

More and more private citizens collect and publish environmental data via web-based geographic information systems. These systems face two challenges: The user interface must be intuitive and the processing of geographic information must account for cognitive impact. We propose to use sketch maps as the medium for interaction, because they reflect a person's spatial knowledge. Information from sketch maps is distorted, schematized, incomplete, and generalized and metric maps are not. This article employs qualitative representations for the alignment of sketch and metric maps. We suggest a set of cognitively oriented aspects in sketch maps stably computed by people and evaluate qualitative representations to formalize these aspects. This allows us to align and integrate geographic information from sketch maps. [ABSTRACT FROM AUTHOR]

Two experiments investigated how people develop different landmark knowledge at decision points. Participants learned a route in a virtual city once or five times. One distinctive landmark was placed at each intersection of the route. At test, participants were released at each intersection according to the learning order and were required to determine the turning direction. At each intersection, the landmark was removed (no landmark), correctly placed (one landmark), duplicated on the other side (two identical landmarks), or misplaced from another intersection (two different landmarks) to disrupt the landmark sequence. The results suggested that humans develop different landmark knowledge (landmark knowledge for guidance, landmark knowledge for place recognition and knowledge of landmark sequence) with different navigation experience. [ABSTRACT FROM PUBLISHER]

Ernest Davis' article “Qualititative Spatial Reasoning in Interpreting Text and Narrative” discusses challenges that the interpretation of natural language appears to raise for the formalization of commonsense spatial reasoning. Davis finds these to be of “surprising logical complexity,” but also “erratic” in that they do not show a logical structuring of the problem space that could guide productive research. In this response I argue that much of the apparent lack of structure Davis laments is due to the very style of formal modeling he pursues. By augmenting logical considerations with substantial input from other disciplines and by adopting a heterogeneous and modular approach to formalization, I suggest that the problem space is by no means as ill-structured as Davis presents it. [ABSTRACT FROM AUTHOR]

A computational approach for comparing qualitative shape descriptions (QSDs) of objects within digital images is presented. First, the dissimilarity of qualitative features of shape is measured: (i) intuitively using conceptual neighborhood diagrams; and (ii) mathematically using interval distances. Then, a similarity measure between QSDs is defined and tested using images of different categories of the MPEG-7-CE-Shape-1 library, images of tiles used to build mosaics, and a collection of Clipart images. The results obtained show the effectiveness of the similarity measure defined, which is invariant to translations, rotations and scaling, and which implicitly manages deformation of shape parts and incompleteness. [ABSTRACT FROM PUBLISHER]

Qualitative spatial reasoning is based on calculi which comprise relations and operation tables that encode operations like relation composition. Designing a calculus involves determining these tables and analyzing reasoning properties—a demanding task that is susceptible to errors if performed manually. This paper is concerned with automating computation of operation tables and analysis of qualitative calculi over real-valued domains like the plane 2. We present an approach to specify qualitative relations using polynomial equations that allows methods from algebraic geometry to be applied. This paper shows how reasoning with qualitative relations can be posed algebraically and demonstrates algebraic reasoning using Gröbner base analysis. We evaluate this approach and describe our implementation, which is freely available as part of the spatial reasoning toolbox SparQ. [ABSTRACT FROM AUTHOR]

Our approach describes any digital image qualitatively by detecting regions/objects inside it and describing their visual characteristics (shape and colour) and their spatial characteristics (orientation and topology) by means of qualitative models. The description obtained is translated into a description logic (DL) based ontology, which gives a formal and explicit meaning to the qualitative tags representing the visual features of the objects in the image and the spatial relations between them. For any image, our approach obtains a set of individuals that are classified using a DL reasoner according to the descriptions of our ontology. [ABSTRACT FROM AUTHOR]

In this paper, we discuss the strategies that languages employ to express motion, focusing on the distinction between path predicates, such as enter, arrive, and leave and manner-of-motion predicates, such as walk, bike, and roll. We present an overview of some qualitative spatiotemporal models of movement, and discuss their adequacy for capturing motion constructions in natural languages. Building on many aspects of these qualitative models, we introduce a framework within dynamic logic for the characterization of spatial change. This model, called Dynamic Interval Temporal Logic (DITL), is developed to analyze both classes of motion predicates, as well as complex compositional constructions involving spatial and manner Prepositional Phrases. Further, DITL serves as a semantics for a linguistically expressive markup language for annotating spatiotemporal information in text, called Spatiotemporal Markup Language (STML). We outline the syntax of this language, and discuss how DITL provides for a natural interpretation of the annotation specification for use in a variety of applications. [ABSTRACT FROM AUTHOR]

In this paper we investigate the application of qualitative spatial reasoning methods for learning the topological map of an unknown environment. We develop a topological mapping framework that achieves robustness against ambiguity in the available information by tracking all possible graph hypotheses simultaneously. We then exploit spatial reasoning to reduce the space of possible hypotheses. The considered constraints are qualitative direction information and the assumption that the map is planar. We investigate the effects of absolute and relative direction information using two different spatial calculi and combine the approach with a real mapping system based on Voronoi graphs. [ABSTRACT FROM AUTHOR]

The article discusses the concept of spatial awareness in using you-are-here maps. Spatial knowledge is categorized into landmark knowledge, route knowledge and survey knowledge. The authors claim that spatial awareness is an important concept for successful orientation, wayfinding and navigation. They add that the ability to create element-to-element correspondence within and between maps is relevant when using a map to create spatial awareness. Overview of papers about spatial awareness published within the issue is also presented.

The article presents an obituary for geography professor and author Reginald G. Golledge.

Alan Turing famously approached intelligence of a machine by its communication behavior. A machine's spatial communication behavior would then define its spatial intelligence, in Turing's sense of successfully imitating human spatial communication behavior. This paper asks whether the time has come for the spatial cognition and computation community to hold a grand challenge on spatial intelligence. [ABSTRACT FROM AUTHOR]

This paper addresses changes of spatial granularity in route directions in relation to information needs in multimodal traveling. We outline a model of variability in granularity and apply this model to empirical data. Results reveal that linguistic route directions produced by humans as well as automatically generated web-based services provide the most crucial route elements in hierarchically structured ways that reflect the salient structure imposed by multimodal traveling. However, although the web-based information is impressively comprehensive, human route directions exhibit more flexibility regarding switches of place-related granularity, and they provide more detailed information at complex locations or decision points. [ABSTRACT FROM AUTHOR]

The nature of route learning in terms of the memorizing of landmarks was investigated. In Experiment 1, participants memorized landmarks while being guided through a computer-simulated hallway (dynamic, with spatial context), or while viewing the landmarks one by one in front of a black background (static, without context). Two more conditions completed the 2 × 2 design. One condition preserved the dynamic landmark viewing properties (observers approached each object, passed it, turned to the next object, and so on), but the background was black (dynamic, without context). In the other condition the observer saw a stationary display of each object within a hallway, but did not approach the object (static, with context). Serial recall was much better after viewing the landmarks in the dynamic presentation format with spatial context than in the other conditions. Experiment 2 showed that the superior performance in the dynamic condition with context was abolished when all hallway segments were equally long. This implies that metric information is a component of route knowledge at a very early stage, which is incompatible with the dominant framework, but is compatible with the alternative framework for spatial microgenesis. [ABSTRACT FROM AUTHOR]

Regionalization has been found to impact human route planning, both when the planning is based on a previously learned environment encoded in memory and when maps are used. This paper presents an experiment in a virtual desktop environment and examines how the length of the path in the start region or goal region impacts ad-hoc route choice, i.e., in situations where the decision is made right after perceiving the decision situation. More specifically, this research aims at quantifying the trade-off value between short travel distances and leaving the start as well as reaching the goal region quicker, respectively. [ABSTRACT FROM AUTHOR]

This paper discusses embedding in a two-dimensional plane a symbolic representation for spatial data using the simple objects, points (P), lines (L), circuits (C), and areas (A). We have proposed PLCA as a new framework for a qualitative spatial reasoning. In a PLCA expression, the entire figure is represented in a form in which all the objects are related. We investigate the conditions for two-dimensional realizability of a PLCA expression, and derive the relation that the numbers of objects in a PLCA expression should have. In this process, we use the well-known Euler's formula. We also give an algorithm for drawing the figure of the PLCA expression that satisfies this condition in a two-dimensional plane and prove its correctness. The algorithm generates a quantitative expression from qualitative expression. [ABSTRACT FROM AUTHOR]

In this paper we propose a spatial ontology for reasoning about holes, rigid objects and a string, taking a classical puzzle as a motivating example. In this ontology the domain is composed of spatial regions whereby a theory about holes is defined over a mereotopological basis. Within this theory we define a data structure, named chain, that facilitates a clear and efficient representation of the puzzle states and its solution. [ABSTRACT FROM AUTHOR]

In order to bridge the gap between natural-language terms and computational model of spatial relations, a complete understanding of the relationship between the ambiguous natural-language representations and the geometric spatial relations of geographic objects is requisite. A human subjects test was conducted to find out how natural-language descriptions of spatial relations of linear objects are determined by the geometric configurations of the objects. The results indicated that both topology and metric properties influent people on choosing spatial predicates to describe spatial relations, but they have different effects on various spatial predicates. Some spatial predicates are mainly affected by topological relations, while metric measures do not have significant effects. Other spatial predicates are primarily affected by metric details, while topology only has secondary effects on them. The categories of geographic entities were found to have effects on the natural-language description in some cases. [ABSTRACT FROM AUTHOR]

The goal of this paper is to present a logic-based formalism for representing knowledge about objects in space and their movements, and show how this knowledge could be built up from the viewpoint of an observer immersed in a dynamic world. In this paper space is represented using functions that extract attributes of depth, size and distance from snapshots of the world. These attributes compose a novel spatial reasoning system named Depth Profile Calculus (DPC). Transitions between qualitative relations involving these attributes are represented by an extension of this calculus called Dynamic Depth Profile Calculus (DDPC). We argue that knowledge about objects in the world could be built up via a process of abduction on DDPC relations. [ABSTRACT FROM AUTHOR]

This paper presents a new proposal for the design of spatio-temporal ontologies which has its origin in cognitively motivated spatial semantics. It is shown that selective attention not only plays a central role in the characterization of spatial relations but that the representation of attentional aspects also leads to the possibility of defining an ontological upper structure which systematically covers both the spatial and the temporal domain. [ABSTRACT FROM AUTHOR]

Interoperability is a crucial problem for geographic information systems. The transfer of data and models between different systems requires the ability to set up a correspondence between concepts in one system to concepts in the other. Concept matching is helped by ontologies. However, the challenge of making ontologies themselves interoperable continues. In other words, given two geo-ontologies, the basic question is: to which degree are these two geo-ontologies interoperable? In this paper, we consider that a geo-ontology describes things that can be assigned to locations on the surface of the Earth and relations between these things. A geo-ontology has concepts that correspond to physical and social phenomena in the real world. We suggest a classification of these concepts based on their use for describing geo-objects. We present a basic set of concepts for a geographical ontology, based on descriptions of the physical world and of the social reality. We also present a framework for measuring the degree of interoperability between geo-ontologies. We consider that this problem is a special case of Bernstein's model management algebra for metadata descriptions. We propose to use a matching operator for measuring interoperability between ontologies. The proposed framework provides a first basis for computational tools that allow a more precise response to problem of ontology interoperability. [ABSTRACT FROM AUTHOR]

In this study, we investigate whether data collected on route knowledge is influenced by the method of data collection. The results of stereoscopic panoramic interactive navigation re-enactment sessions and conventional paper and pencil maps are compared against observational tracing data of pedestrian route choice behavior in the city center of Eindhoven, The Netherlands. The findings of the study suggest that the data collected through maps better describe empirical observations of pedestrian route choice behavior that the data collected through stereoscopic panoramic interactive navigation sessions. [ABSTRACT FROM AUTHOR]