User interaction with online geospatial systems

User interaction with online geospatial systems is an inter-disciplinary research field that combines the two disciplines Human Computer Interaction (HCI) and geographic information sciences. In recent years online geospatial systems have been created for different purposes such as way-finding systems, online atlases and collaborative systems. In order to accommodate the fact that an increasing number of people have access to geospatial data and technology, research has begun to focus on the impact and the utilization of such systems. However few studies regarding the usability of online geospatial systems have been conducted and most of these studies were set up in artificial lab-environments with few mostly poorly described test-users. Furthermore to the best of our knowledge no formal research framework currently exists that allows for analyzing the interaction of real-world users with such systems and that takes into account the spatial nature of these systems. The goal of this thesis is to show that users, depending on their demographics, experience, skills and context show significant differences in their interaction strategies and performance. Another important factor that has been neglected in many recent laboratory-based usability studies is the user's computer. In this work, we want to show that users, depending on their computer's properties show significant differences regarding their interaction strategies, their performance and satisfaction. The work in this thesis consists of three parts: 1. the establishment of an evaluation framework that categorizes and defines the interaction of real-world users with geospatial systems. The four main entities of this framework are the user (in terms of demographics, skills, knowledge and context), the system (defined by the interface design, spatial data, spatial functions, technologies and architectures), the user interaction (interaction strategies, performance and perception of spatial data), and the satisfaction of using the system. 2. the development of methods and software tools for gathering experimental data based on the four entities of the evaluation framework 3. the validation of the evaluation framework with case studies involving systems that have been developed for specific groups of end-users. We have conducted three case studies where real-world users interact with three online geospatial systems. The important findings of those studies were that there are noticeable gender differences regarding spatial navigation, that user satisfaction appears to be biased by the user's previous experience with geographic information technologies and that the type of the input device used (e.g. mouse or touchpad) has a considerable influence on task-completion time and user satisfaction. The above results indicate that the user's demographic parameters and background have a significant effect on the user's spatial interaction strategies, performance and satisfaction. Furthermore we have found evidence that suggests that the user's perception of spatial data strongly depends on the scale. We conclude that the design and development of spatial interaction functions (spatial navigation, digitization, selection of objects and locations) in online geospatial systems should highly depend on the type of users that the systems are developed for. To further fuel research on usability aspects of online geospatial systems, we provide the necessary tools and methods for conducting remote- and laboratory based testing of such systems.

Approche systémique et participative du diagnostic urbain

Gilles Desthieux

Social, economic and environmental phenomena as well as the presence of groups of stakeholders with diverging and contradictory interests highlight the complexity of urban projects. Traditional instruments of urban management are seldom adapted to these challenges, as they are often founded on sector- and expert-based approaches. Furthermore geographical information is paradoxically often available in a very large quantity, but not sufficiently relevant and synthetic for an understanding of urban complexity. In this context the goal of this thesis is to develop a method for the elaboration of relevant indicators systems from different stakeholders' cognitive representations of urban complexity; and thus to reinforce territorial diagnosis in the context of participative decision-making processes. However these differences of representations are often sources for conflicts. Each stakeholder uses his own representation in order to defend his point of view in a debate. The notice of these differences, from the "problem setting" phase of the decision-making process should contribute to a better structured debate and to a better management of the conflicts around a territorial project. This goal can be reached through consideration of all opinions and through an establishment of a discussion-space between different groups of representations. This allows the development of a coherent diagnosis framework which includes different stakeholders' cognition and perception of the territorial context. Our reflection is concretized by the developing of a prototype of interface that help a stakeholder to construct his own representation or urban phenomena, by organizing them in a dialectic (discussions) and didactic (complexity-training) manner. The phenomena-systems created are in the form of a causal model. The interpretation of this model permits to highlight critical phenomena through considering the preferred causal axes in order to output the stakeholder's goals. On this basis the stakeholder can debate and discuss with other stakeholders who also have constructed their own representations. From these individual representations, the question is how these representations can be integrated to form a collective representation of the territory. This process can be made in a deliberative manner. Before that, it is proposed to structure the debate by regrouping individuals models using analytical tools (classification, aggregation). Converging (collective reasons) and diverging elements of the urban complexity understanding are emphasized in the groups of models. The idea is thus to create a discussion-space for debates in order to find solutions. On the basis of different representation-groups, indicators-systems can be proposed. Indicators are selected in order to translate on one hand common representation of the main phenomena identified, on the other hand of causal relationships that result in strong differences. These indicators can contribute to a partial solution of conflicts by adding another, more objective point of view in the territorial context. Indicators are developed using spatio-thematical operators of geographical information systems. A concept of interface is proposed so as to facilitate the communication of systems of geographical indicators. In order to emphasis our approach, we have illustrated and applied the methodology of systemic urban-phenomena-modeling. We have conducted individual interviews with stakeholders who have participated in a diagnosis process in a neighborhood of Geneva and with stakeholders who are implied in suburban problematic in Québec. These discussions have shown the interest in our approach to help these stakeholders to formalize their representation of urban dynamics. In the same way, regrouping methods have proved their capability to reveal differentiated models of representation between groups of stakeholders. The method described presents an interest in participative decision-making and creates an advantageous framework for the interaction between these stakeholders around the representation of urban reality. The indicators-system contributes to this process and connects the representation of the territory and different stakeholders' cognitive representations according to a dynamic learning process. From this more solid and objectified basis the development of a diagnosis can succeed and the decision-making process can continue towards more operational phases.

EPFL2005

Contribution du SIG à l'analyse des liens déchets-santé en milieu urbain dans les pays en développement

Sonwouignandé Kientga

Among the factors of health risks in urban areas, the solid and liquid wastes worsen particularly the problems of public health in developing countries. Uncontrolled solid waste disposal sites and waste water sites constitute major sources of danger for public health. Often, there is no mapped and documented inventory. The perception of danger related to infectious sources by the exposed populations is generally not well-known and even often ignored by the public institutions in their management policy of health and wastes. The same can be considered for the link between diagnosed diseases in health care services and the presence of waste disposal sites near patients' residences. The goal of this study is to determine the main factors of waste management and their consequences on health. This goal shall be reached using a GIS approach and through a case study concerning two districts in the town of Ouagadougou in Burkina Faso. In detail, the objectives are: i) to build a spatial database for waste disposal sites and public health care management and to propose a methodological approach for the elaboration of a GIS, associating social science, health and the geographical information science; ii) to identify and to analyze indicators of public health related to domestic and industrial waste; ii) to compare these indicators with the different actors' perception, according to the distance and dangers represented by the seriousness of potential danger sources; iv) to analyze if there is a relation between the actors' perception and the diseases diagnosed in health care services; v) to promote GIS in institutional structures in order to facilitate decision-making in waste management. Geographical information science has contributed to the creation of a database containing general geographical data, the disposal waste sites, the data of the actors' perception and health data. This database was used for spatial-thematic, temporal and statistical analyses. At first we have established an inventory of disposal waste sites. Hereafter we have analyzed their spatial influence. We then compared the situation to the perception of dangers and to the people's health risks, related to the distance to sources of potential danger. An analysis of the relation between the disease cases listed (counted) in health centers and the presence of waste (infectious) sources was carried out. This allowed some degree of comparison between the subjectivity of danger perception and the reality. The inventory of potential danger sources and the analysis of their influence spheres shows that 86 % (456 ha) of the study area is threatened by a danger, among which 45 % (235 ha) are considered exposed to a higher danger. The results also show that only 14 % of the population in both sectors (2'574 inhabitants of 18'978 total inhabitants) is not exposed to potential health risks. The analysis of the perceived danger according to the distance revealed that the perceived danger generally decreases proportionally to the distance. Surprisingly certain persons living near a polluted site don't consider the site as dangerous. However others, living far away from the same site, perceive it as dangerous. In these cases the subjective dimension of the perception is thus revealed. The temporal analyses of listed diseases show a correlation between the cases of malaria and the precipitation. The time gap between precipitation-related peaks and malaria cases related peaks varies from two to three months, leaving enough time to take preventive measures. We were not able to establish a link between the patient's residence and pollution sources; because the patient's geographical location is not mentioned in the health care services' registers. A modification of the registration forms has been suggested. The developed methodology and the results gathered led to the establishment of suggestions and recommendations based on the integration of GIS in waste and health management. This study has already contributed to the setup of a geo-information network composed of various actors in waste and health management.

EPFL2008

Introducing SMURF: a software system for monitoring urban functionalities

André Musy, Alexandre Repetti, Marc Soutter

Urban land-use planning and management are in constant mutation throughout the world. With sustainability as a goal, the use of participative GIS is becoming more and more in demand. Given the willingness of local authorities to test participatory models and instruments, this paper presents an original implementation of information and communication technologies to support public participation. A system for monitoring urban functionalities (SMURF) was created for supporting participatory planning and management in African cities. The software instrument consists of a geographic database and of spatial indicators, for sharing information, editing information, and evaluating city development. To collect and update data, the model begins with the gathering of the data from each stakeholder, who, in return, gets a better knowledge of the land and a planning support tool. However, the implementation of these technologies presents several challenges: create an adapted interface, elaborate a relevant set of data and indicators, manage the data, and institutionalize the instrument. After an introductory presentation of the context and use of information technologies for the management of African cities, this paper focuses on SMURF and its components. It then shows the experimental application of the software in the city of Thies, Senegal, before concluding with a more general discussion on the relationship between technology, information, knowledge, and participation.