Michotte's theory of ampliation suggests that causal relationships are perceived by objects animated under appropriate spatiotemporal conditions. In this thesis I extend the theory of ampliation and propose that the immediate perception of complex causal relations is also dependent upon a set of structural and temporal rules. The thesis aims at achieving two main goals. The first goal is to define a taxonomy of semantics that describe different causal events in the environment. Ten semantics are defined in this thesis and divided into two main groups; simple causal semantics and complex causal semantics. Simple causal semantics describe basic semantics, which form the building blocks for more complex information and include causal amplification, causal dampening, causal strength, and causal multiplicity. Complex causal semantics are built by enhancing or combining one or more simple semantics and include additive causality, contradictive causality, fully-mediated causality, partially-mediated causality, threshold causality, and bidirectional causality. The second goal of this thesis is to design simple visual representations to describe the causal information. Three representation types were designed during the course of this research; static-graph, static-sequence, and animation. Nine experiments were also conducted to test the effectiveness of these representations. The first five experiments compared the static-graph and the animated representations through Memory Recall and Intuitiveness Evaluations tests. Results of these experiments suggest that animations were ~8% more accurate and performed ~9% faster than the static-graph representations. The last four experiments compared an enhanced static representation, called static-sequence, to the animations to test if sequential animation of causal relations had any influence on the superior performance of the animations in the previous experiments. Results of these experiments suggest that there was no significant difference in the performance of the static-sequence representations when compared to the static-graph representations. The results also suggest that the animations performed more accurately than their static counterparts mainly due to their intuitiveness. Overall our results show that animated diagrams that are designed based on perceptual rules such as those proposed by Michotte have the potential to facilitate comprehension of complex causal relations.

Michotte's theory of ampliation suggests that causal relationships are perceived by objects animated under appropriate spatiotemporal conditions. In this thesis I extend the theory of ampliation and propose that the immediate perception of complex causal relations is also dependent upon a set of structural and temporal rules. The thesis aims at achieving two main goals. The first goal is to define a taxonomy of semantics that describe different causal events in the environment. Ten semantics are defined in this thesis and divided into two main groups; simple causal semantics and complex causal semantics. Simple causal semantics describe basic semantics, which form the building blocks for more complex information and include causal amplification, causal dampening, causal strength, and causal multiplicity. Complex causal semantics are built by enhancing or combining one or more simple semantics and include additive causality, contradictive causality, fully-mediated causality, partially-mediated causality, threshold causality, and bidirectional causality. The second goal of this thesis is to design simple visual representations to describe the causal information. Three representation types were designed during the course of this research; static-graph, static-sequence, and animation. Nine experiments were also conducted to test the effectiveness of these representations. The first five experiments compared the static-graph and the animated representations through Memory Recall and Intuitiveness Evaluations tests. Results of these experiments suggest that animations were ~8% more accurate and performed ~9% faster than the static-graph representations. The last four experiments compared an enhanced static representation, called static-sequence, to the animations to test if sequential animation of causal relations had any influence on the superior performance of the animations in the previous experiments. Results of these experiments suggest that there was no significant difference in the performance of the static-sequence representations when compared to the static-graph representations. The results also suggest that the animations performed more accurately than their static counterparts mainly due to their intuitiveness. Overall our results show that animated diagrams that are designed based on perceptual rules such as those proposed by Michotte have the potential to facilitate comprehension of complex causal relations.

Même si la réduction des apports de nutriments dans les écosystèmes aquatiques est généralement envisagée avec des approches « effects-based », ce n’est pas le cadre qui a été suivi dans cette thèse. En effet, dans une démarche de développement durable, il semble plus pertinent, de définir des mesures de contrôle de la pollution agissant sur les relations de cause à effet. Selon cette logique, la méthodologie proposée par la Directive Cadre sur l’Eau (DCE) pour protéger les écosystèmes aquatiques présente plusieurs faiblesses. Par le fait qu’elle réfère à certains principes de l’économie standard de l’environnement, l’analyse économique de la DCE pose plusieurs problèmes pour agir sur la causalité de la pollution. Néanmoins, la méthodologie proposée par la DCE est pertinente par le fait qu’elle recommande l’utilisation combinée de mesures techniques et d’instruments pour diminuer les dommages environnementaux. Conformément à cette disposition, l’effet de mesures techniques et d’instruments sur le secteur agricole et sur la chaine alimentaire l’englobant a été évalué puisque cette dernière est responsable de la majorité des émissions diffuses et ponctuelles d’azote et de phosphore dans les eaux de surface. La définition de mesures techniques en fonction de l’efficience de l’utilisation des nutriments (Nutrient Use Efficiency, NUE) dans la production agricole a été complétée par l’étude des instruments économiques utilisés dans la Politique Agricole Commune (PAC) pour développer une agriculture multifonctionnelle. Si la thèse concerne de manière générale l’eutrophisation des écosystèmes aquatiques, elle se penche plus particulièrement sur les pressions au sein du bassin de l’Escaut et sur leurs impacts jusqu’à la zone côtière de la mer du Nord. Des mesures techniques agissant sur les causes des émissions diffuses du secteur agricole et sur les émissions ponctuelles des stations d’épuration ont été proposées pour ce bassin. Ces mesures techniques ont été caractérisées prioritairement par leur efficacité environnementale (grâce aux modèles Sénèque-Riverstrahler et MIRO) et en fonction de leurs coûts directs. <p><p>/<p><p>Although reducing the load of nutrients in aquatic ecosystems is usually looked at through "effects-based" approaches, this is not the context which this paper has chosen to follow. In fact, keeping in line with sustainable development, it seems more relevant to define measures to control pollution which act on cause and effect relations. According to this way of thinking, the methodology proposed by the Water Framework Directive (WFD) to protect aquatic ecosystems presents a number of weaknesses. By the fact that it refers to certain standard economic principles for the environment, the WFD’s economic analysis poses several problems towards acting on the cause of the pollution. Nevertheless, the methodology proposed by the WFD is relevant, as it recommends the combined use of technical measures and of instruments to reduce environmental damage. In accordance with this disposition, an assessment has been made of the effect of technical measures and instruments on the agricultural sector and on the food chain encompassing it, since the food chain is responsible for the majority of diffuse and point emissions of nitrogen and phosphorus in surface waters. The definition of technical measures in terms of efficient use of nutrients (Nutrient Use Efficiency, NUE) in agricultural production has been complemented by a study of economic instruments used in the Common Agricultural Politicy (CAP) to develop a multifunctional type of agriculture. Although the paper deals with the eutrophication of aquatic ecosystems in a general way, it concentrates particularly on the increasing pressures in the Scheldt basin and on their impacts as far as the North Sea coastal zone. Technical measures acting on the causes of diffuse emissions in the agricultural sector and on point emissions in the water treatment plants have been proposed for this basin. These technical measures have been categorised in order of priority according to their environmental effectiveness (thanks to the Sénèque-Riverstrahler et MIRO models) and depending on their direct costs. / Doctorat en Sciences agronomiques et ingénierie biologique / info:eu-repo/semantics/nonPublished