While the presence of uncertainty in the geometric and attribute aspects of geographic information is well known, it is also present in temporal information. In spatiotemporal GIS databases and other formal representations, uncertainty in all three aspects of geography (space, time, and theme) must often be modeled, but a good data model must first be based on a sound theoretical understanding of spatiotemporal uncertainty. The nature of both uncertainty inherent in a phenomenon (often termed indeterminacy) and uncertainty in assertions of that phenomenon can be better understood through the Uncertain Temporal Entity Model, which characterizes the cause, type, and form of uncertainties in the spatial, temporal, and attribute aspects of geographic information. These uncertainties are the result of complexities and problems in two processes: the process of conceptualization, by which humans make sense of an infinitely complex reality, and measurement, by which we create formal representations (e.g. GIS) of those conceptual models of reality. Based on this framework, the nature and form of uncertainty is remarkably consistent across various situations, and is approximately equivalent in the three aspects, which will enable consistent solutions for representation and processing of spatiotemporal data.
A computational framework is presented for re-engineering the Geographic Information Science and Technology Body of Knowledge (GIS&T BoK). At its core is an ontology that is meant to simplify and extend the original BoK hierarchical structure to better capture relationships existing among concepts. Our approach builds on several key ideas. First is the notion of a knowledge corpus, an aggregate of both the internal cognitive forms of knowledge held by domain actors and the content of external artifacts that are produced and consumed by domain activities. Second is the notion of a reference system within which such artifacts are located and relationships among artifacts can be expressed. Third is the idea that by structuring the GIS&T concepts through the use of semantic web standards for formal ontologies and envisaging it as a reference system for GIS&T artifacts, activities, and actors, a fundamentally different approach to the redesign, content generation, and maintenance of the GIS&T BoK is enabled. This new approach affords replacing the top-down strategies used to generate the original GIS&T BoK, with a bottom-up strategy that combines analytical and participatory components. On the analytical side, computational and visual techniques are used to provide alternative means for accessing BoK content, examining the semantic consistency of current BoK structures, transforming the existing hierarchy into a semantic network, identifying overlaps and gaps in the current BoK, and performing projection of knowledge artifacts onto the BoK to inform its maintenance and update. Participatory approaches to bottom-up restructuring and maintenance of the BoK will support authoring, editing, and validation of concepts using a wiki-like community editing service. The system we describe is deployed as a web service that can be accessed by a range of applications for visualization, analysis, exploration, and contextualization of concepts and their related classes in the new GIS&T Body of Knowledge. The goal is for the new GIS&T BoK2 to evolve into the centerpiece of a cyberinfrastructure ecosystem for the GIS&T domain.
Academic institutions are increasingly being held accountable for the quality of education which is, in turn, leading to an increased emphasis on curriculum assessment. This is especially true of geographic information science & technology (GIS&T), in which a rapidly growing profession demands that educational programs produce highly qualified graduates. In response to these demands, the University Consortium of Geographic Information Science (UCGIS) has developed the Geographic Information Science and Technology Body of Knowledge, to identify the broad spectrum of knowledge, skills and techniques that make up the GIS&T domain. An intended use of this document is to support the development and assessment of GIS&T curricula. The authors address the potential benefits of using the Body of Knowledge through an evaluation of the learning objectives and curriculum of sample courses at two universities. They find that the Body of Knowledge enables robust specification of objectives and curricula, and provides the platform for reproducible and consistent evaluation of both curriculum and, ultimately, student outcomes. It is also flexible in allowing programmes to evaluate curricula based on their own goals and missions, rather than against a single standard curriculum.
Historical place databases can be an invaluable tool for capturing the rich meaning of past places. However, this richness presents obstacles to success: the daunting need to simultaneously represent complex information such as temporal change, uncertainty, relationships, and thorough sourcing has been an obstacle to historical GIS in the past. The Qualified Assertion Model developed in this paper can represent a variety of historical complexities using a single, simple, flexible data model based on a) documenting assertions of the past world rather than claiming to know the exact truth, and b) qualifying the scope, provenance, quality, and syntactics of those assertions. This model was successfully implemented in a production-strength historical gazetteer of religious congregations, demonstrating its effectiveness and some challenges.
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