PhD supervision

Automation enables systems to execute some functions without outside control and to adapt functions they execute to new contexts and goals. Systems with automation are used more and more to help humans in everyday tasks with, for example, the dishwasher. Systems with automation are also used to help humans in their professional life. For example, in the field of aeronautics, automation has gradually reduced the number from 4 pilots to 2 pilots. Automation was first considered as a way to increase performance and reduce effort by migrating tasks previously allocated to humans to systems. This, in the hypothesis that systems would be better than humans would at performing certain tasks and vice-versa. Paul Fitts proposed MABA-MABA (Machine Are Better At – Man Are Better At), a tasks and functions allocation method based on this hypothesis. In line with this hypothesis, various descriptions of levels of automation have been proposed. The 10 levels of Automation (LoA) by Parasuraman, Sheridan et Wickens describe different tasks and functions allocations between the human and the system. The higher the level of automation, the more tasks migrate from human to system. These approaches have been the subject of criticism. « MABA-MABA or Abracadabra? Progress on Human–Automation Coordination » of Dekker and Woods highlights that automation leads to new tasks allocated to humans to manage this automation. Moreover, they recall that these approaches hide the cooperative aspect of the human-system couple. To characterize the human-system cooperation, the importance of considering, at design time, the allocation of authority, responsibility, control and the initiative to modify these allocations during the activity was demonstrated. However, the existing approaches describe a high-level design of automation and cooperation early in the design and development process. These approaches does not provide support for reasoning about the allocation of resources, control transitions, responsibility and authority throughout the design and development process. The purpose of this thesis is to demonstrate the possibility to analyze and describe at a low-level tasks and functions as well as the cooperation between humans and the system with automation. This analysis and this description enable to characterize tasks, functions and the cooperation in terms of authority, responsibility, resource sharing and control transition initiation. The aim of this work is to provide a framework and a model-based tooled process to analyze and understand automation. In order to show the feasibility of this approach, this thesis presents the results of the application of the proposed process to an industrial case study in the field of aeronautics.

On-going thesis

In user-centered approaches, the techniques, methods, and development processes used aim to know and understand the users (analyze their needs, evaluate their ways of using the systems) in order to design and develop usable systems that is in line with their behavior, skills and needs. Among the techniques used to guarantee usability, task modeling makes it possible to describe the objectives and activities of the users. With task models, human factors specialists can analyze and evaluate the effectiveness of interactive applications. This approach of task analysis and modeling has always focused on the explicit representation of the standard behavior of the user. This is because human errors are not part of the users' objectives and are therefore excluded from the job description. This vision of error-free activities, widely followed by the human-machine interaction community, is very different from the Human Factor community vison on user tasks. Since its inception, Human Factor community has been interested in understanding the causes of human error and its impact on performance, but also on major aspects like the reliability of the operation and the reliability of the users and their work. The objective of this thesis is to demonstrate that it is possible to systematically describe, in task models, user errors that may occur during the performance of user tasks. For this demonstration, we propose an approach based on task models associated with a human error description process and supported by a set of tools. This thesis presents the results of the application of the proposed approach to an industrial case study in the application domain of aeronautics.

In a user-centered design process, artifacts evolve in iterative cycles until they meet user requirements and then become the final product. Every cycle gives the opportunity to revise the design and to introduce new requirements which might affect the artifacts that have been set in former development phases. Keeping the consistency of requirements in such artifacts along the development process is a cumbersome and time-consuming activity, especially if it is done manually. Nowadays, some software development frameworks implement Behavior-Driven Development (BDD) and User Stories as a means of automating the test of interactive systems under construction. Automated testing helps to simulate user’s actions on the user interface and therefore check if the system behaves properly and in accordance with the user requirements. However, current tools supporting BDD requires that tests should be written using low-level events and components that only exist when the system is already implemented. As a consequence of such low-level of abstraction, BDD tests can hardly be reused with more abstract artifacts. In order to prevent that tests should be written to every type of artifact, we have investigated the use of ontologies for specifying both requirements and tests once, and then run tests on all artifacts sharing the ontological concepts. The resultant behavior-based ontology we propose herein is therefore aimed at raising the abstraction level while supporting test automation on multiple artifacts. This thesis presents this ontology and an approach based on BDD and User Stories to support the specification and the automated assessment of user requirements on software artifacts along the development process of interactive systems. Two case studies are also presented to validate our approach. The first case study evaluates the understandability of User Stories specifications by a team of Product Owners (POs) from the department in charge of business trips in our institute. With the help of this first case study, we designed a second one to demonstrate how User Stories written using our ontology can be used to assess functional requirements expressed in different artifacts, such as task models, user interface (UI) prototypes, and full-fledged UIs. The results have shown that our approach is able to identify even finegrained inconsistencies in the mentioned artifacts, allowing establishing a reliable compatibility among different user interface design artifacts.

In user-centered approaches, the techniques, methods, and development processes used aim to know and understand the users (analyze their needs, evaluate their ways of using the systems) in order to design and develop usable systems that is in line with their behavior, skills and needs. Among the techniques used to guarantee usability, task modeling makes it possible to describe the objectives and activities of the users. With task models, human factors specialists can analyze and evaluate the effectiveness of interactive applications. This approach of task analysis and modeling has always focused on the explicit representation of the standard behavior of the user. This is because human errors are not part of the users' objectives and are therefore excluded from the job description. This vision of error-free activities, widely followed by the human-machine interaction community, is very different from the Human Factor community vison on user tasks. Since its inception, Human Factor community has been interested in understanding the causes of human error and its impact on performance, but also on major aspects like the reliability of the operation and the reliability of the users and their work. The objective of this thesis is to demonstrate that it is possible to systematically describe, in task models, user errors that may occur during the performance of user tasks. For this demonstration, we propose an approach based on task models associated with a human error description process and supported by a set of tools. This thesis presents the results of the application of the proposed approach to an industrial case study in the application domain of aeronautics.

The work of this thesis aims at contributing to the field of the engineering of interactive critical systems. We aim at easing the introduction of new input and output devices (such as touch screens, mid-air gesture recognition ...) allowing multi-user and multimodal interactions in next generation of aircraft’s cockpits. Currently, development process in the aeronautical filed is not compatible with the complexity of multimodal interaction. On the other side development process of wide spread systems cannot meet the requirements of critical systems. We introduce a generic software and hardware architecture model called MIODMIT (Multiple Input Output devices Multiple Interaction Techniques) which aim the introduction of dynamically instantiated devices, allowing multimodal interaction in critical systems. It describes the organization of information flux with a complete and non-ambiguous way. It covers the entire spectrum of multimodal interactive systems, from input devices and their drivers, to the specification of interaction techniques and the core of the application. It also covers the rendering of every software components, dealing with fission and fusion of information. Furthermore, this architecture model ensure the system configuration modifiability (i.e. add or suppress a device in design or operation phase). Furthermore, moralizing a system reveals that an important part of the interactive part is autonomous (i.e. not driven by the user). This kind of behavior is very difficult to understand and to foresee for the users, causing errors called automation surprises. We introduce a model-based process of evaluation of the interaction techniques which decrease significantly this kind of error. Lastly, we exploited ICO (Interactive Cooperative Objects) formalism , to describe completely and unambiguously each of the software components of MIODMIT. This language is available in an IDE (integrated development environment) called Petshop, which can execute globally the interactive application (from input/output devices to the application core). We completed this IDE with an execution platform named ARISSIM (ARINC 653 Standard SIMulator), adding safety mechanisms. More precisely, ARRISIM allows spatial segregation of processes (memory allocution to each executing partition to ensure the confinement of potential errors) and temporal segregation (sequential use of processor). Those adding increase significantly the system reliability during execution. Our work is a base for multidisciplinary teams (more specifically ergonoms, HMI specialist and developers) which will conceive future human machine interaction in the next generation of aircraft cockpits.

The current European Air Traffic Management (ATM) System needs to be improved for coping with the growth in air traffic forecasted for next years. It has been broadly recognised that the future ATM capacity and safety objectives can only be achieved by an intense enhancement of integrated automation support. However, increase of automation might come along with an increase of performance variability of the whole ATM System especially in case of automation degradation. ATM systems are considered complex as they encompass interactions involving humans and machines deeply influenced by environmental aspects (i.e. weather, organizational structure) making them belong to the class of Socio-Technical Systems (STS) (Emery & Trist, 1960). Due to this complexity, the interactions between the STS elements (human, system and organisational) can be partly linear and partly non-linear making its performance evolution complex and hardly predictable. Within such STS, interactive systems have to be usable i.e. enabling users to perform their tasks efficiently and effectively while ensuring a certain level of operator satisfaction. Besides, the STS has to be resilient to adverse events including potential automation degradation issues but also interaction problems between their interactive systems and the operators. These issues may affect several STS aspects such as resources, time in tasks performance, ability to adjust to environment, etc. In order to be able to analyse the impact of these perturbations and to assess the potential performance variability of a STS, dedicated techniques and methods are required. These techniques and methods have to provide support for modelling and analysing in a systematic way usability and resilience of interactive systems featuring partly autonomous behaviours. They also have to provide support for describing and structuring a large amount of information and to be able to address the variability of each of STS elements as well as the variability related to their interrelations. Current techniques, methods and processes do not enable to model a STS as a whole and to analyse both usability and resilience properties. Also, they do not embed all the elements that are required to describe and analyse each part of the STS (such as knowledge of different types which is needed by a user for accomplishing tasks or for interacting with dedicated technologies). Lastly, they do not provide means for analysing task migrations when a new technology is introduced or for analysing performance variability in case of degradation of the newly introduced automation. Such statements are argued in this thesis by a detailed analysis of existing modelling techniques and associated methods highlighting their advantages and limitations. This thesis proposes a multi-models based approach for the modelling and the analysis of partly-autonomous interactive systems for assessing their resilience and usability. The contribution is based on the identification of a set of requirements needed being able to model and analyse each of the STS elements. Some of these requirements were met by existing modelling techniques, others were reachable by extending and refining existing ones. This thesis proposes an approach which integrates 3 modelling techniques: FRAM (focused on organisational functions), HAMSTERS (centred on human goals and activities) and ICO (dedicated to the modelling of interactive systems). The principles of the multi-models approach is illustrated on an example for carefully showing the extensions proposed to the selected modelling techniques and how they integrate together. A more complex case study from the ATM domain is then presented to demonstrate the scalability of the approach. This case study, dealing with aircraft route change due to bad weather conditions, highlights the ability of the integration of models to cope with performance variability of the various parts of the STS.

With the advent of new technologies such as the iPad, general public software feature richer and more innovative interfaces. These innovations are both on the input layer (e.g. multi-touch screens) and on the output layer (e.g. display). These interfaces are categorized as post-W.I.M.P. type and allow to increase the bandwidth between the user and the system he manipulates. Specifically it allows the user to more quickly deliver commands to the system and the system to present more information to the user enabling him managing increasingly complex systems. The large use in the general public and the level of maturity of these technologies allows to consider their integration in critical systems (such as cockpits or more generally control and command systems). However, the software issues related to these technologies are far from being resolved judging by the many problems encountered by users. While the latter may be tolerated for gaming applications and entertainment, it is not acceptable in the field of critical systems described above. The problem of this thesis focuses specifically on the development of methods, languages, techniques and tools for the design and development of innovative and reliable interactive systems. The contribution of this thesis is the extension of a formal notation: ICO (Interactive Cooperative Object) to describe in a complete and unambiguous way multi-touch interaction techniques and is applied in the context of multi-touch applications for civilians aircrafts. We provide in addition to this notation, a method for the design and validation of interactive systems featuring multi-touch interactions. The mechanisms of these interactive systems are based on a generic architecture structuring models from the hardware part of the input devices up to the application part for the control and monitoring of these systems. This set of contribution is applied on a set of case studies, the most significant being an application for weather management in civilian aircrafts

Currently, a lot of the tasks engaged by users over the Web involve dealing with multiple Web sites. Moreover, whilst Web navigation was considered as a lonely activity in the past, a large proportion of users are nowadays engaged in collaborative activities over the Web. In this paper we argue that these two aspects of collaboration and tasks spanning over multiple Web sites call for a level of coordination that require Distributed User Interfaces (DUI). In this context, DUIs would play a major role by helping multiple users to coordinate their activities whilst working collaboratively to complete tasks at different Web sites. For that, we propose in this paper an approach to create distributed user interfaces featuring procedures that are aimed to orchestrate user tasks over multiple Web sites. Our approach supports flexible process modeling by allowing users to combine manual tasks and automated tasks from a repertoire of patterns of tasks performed over the Web. In our approach, whilst manual tasks can be regarded as simple instructions that tell users how to perform a task over a Web site, automated tasks correspond to tools built under the concept of Web augmentation (as it augments the repertoire of tasks users can perform over the Web) called Web augmenters. Both manual and automated tasks are usually supported by specific DOM elements available in different Web sites. Thus, by combining tasks and DOM elements distributed in diverse Web sites our approach supports the creation of procedures that allows seamless users interaction with diverse Web site. Moreover, such an approach is aimed at supporting the collaboration between users sharing procedures. The approach is duly illustrated by a case study describing a collaborative trip planning over the Web.

Graphical User Interfaces used to be mostly static, representing one software state after the other. However, animated transitions between these static states are an integral part in modern user interfaces and processes for both their design and implementation remain a challenge for designers and developers. This thesis proposes a process for designing interactive systems focusing on animations, along with an architecture for the definition and implementation of animation in user interfaces. The architecture proposes a two levels approach for defining a high-level view of an animation (focusing on animated objects, their properties to be animated and on the composition of animations) and a low-level one dealing with detailed aspects of animations such as timing and optimization. For the formal specification of these two levels, we are using an approach facilitating object-oriented Petri nets to support the design, implementation and validation of animated user interfaces by providing a complete and unambiguous description of the entire user interface including animations. Finally, we describe the application of the presented process exemplified by a case study for a high-fidelity prototype of a user interface for the interactive Television domain. This process will lead to a detailed formal specification of the interactive system, including animations using object-oriented Petri nets (designed with the PetShop CASE tool).

Since the Airbus A380 and with the introduction of ARINC 661 standard, the glass cockpits are being replaced by interactive cockpits, by allowing the crew to control aircraft systems through display unit by using keyboard and cursor control unit (KCCU). Currently only secondary aircraft systems which are non-critical are managed using such interactive cockpits. To be able to generalize such features to critical aircraft system, the main question remains to understand how to match dependability requirements for such systems while preserving usability roperties. To reach the goal of using such interactive techniques within safety critical aircraft systems, our research work has followed three main directions. The first approach is to tend to zero default design, by realizing the precise and unambiguous description of software components of interactive system, using formal description technique. The second approach consists in the use of fault tolerant mechanisms, to treat design residual fault, physical fault or environmental fault. These fault tolerant mechanisms enable the continuity of service despite the occurrence of fault. The third approach is the clarification of the impact of different fault tolerant mechanisms on the usability of the interactive system. This clarification is done by using and analyzing task models, describing the user activity of the system.

User Centered Design is today a reference to design and develop interactive systems. All the existing techniques, methods and development processes based on this paradigm are targeting to understand and know the user. They aim at designing and developing systems that match their needs, skills and behaviours. These techniques, methods and development processes are improved regularly and are spreading through the mass market industries. The underlying philosophy is to focus on the affordance of the designed system, so that it will be used efficiently and that it will give satisfaction to the user, even at first use. However, in the case of interactive critical systems (in the application domains of aeronautics, aerospace or nuclear energy for example), the cost of a usage error or of a system failure can overcome the cost of the development of the system itself, and can result in loss of life, injury or damage to the system and its environment. User Centered Design techniques, methods and processes are then not sufficient, as they are not handling all of the design and development issues that are associated to interactive critical systems. First of all, these techniques, methods and processes do not enable to guarantee that the system will fulfil both usability and reliability properties. Then, they do not consider training and qualification of the users of the system. At last, they do not provide means for traceability of the needs and requirements through the whole development process. This thesis states that it is possible to develop an interactive critical system and its associated training program, in an integrated way, in order to guarantee that the system fulfils properties of usability, reliability and operability, and that the users are qualified before using the system. To demonstrate this statement, we analyse existing development processes, techniques and methods and we highlight their advantages and limitations. From the outcome of our study, we propose an approach to develop interactive critical systems that are usable, reliable and operable and we describe the associated conceptual framework of our approach. We propose an implementation of this approach with a development process, notations and a software environment. The development process integrates phases for the development of the associated training program, and it provides support for the traceability of requirements and design choices during the whole phases of the process. This approach takes advantages from the User Centered Design paradigm and uses, in a synergistic way, task models, system's behaviour formal models and training program development model. We also propose a new task modelling notation, HAMSTERS (Human-centered Assessment and Modelling to Support Task Engineering for Resilient Systems), in addition to an extension of the TEAM (Traceability Exploration and Analysis Model) design rationale notation, and a synergistic modelling and prototyping software environment. The proposed development process, notations and software environment are applied in several examples and in a large case study of the development of a satellite command and control ground segment application.

Designing a highly interactive application implies to make a compromise between the efficiency of the graphical renderer and the expressive power offered to the graphical designer. Thus, classical WIMP toolkits are powerful in terms of rendering, but do not allow the user to finely tune the final rendering of the graphics, or to change their behavior. In order to enhance the process of designing graphical applications and the usability to reuse them, the description of the interactive part has to be separated from the implementation and the optimizations. This thesis presents dfferent way to separate description from optimizations. First, it presents Hayaku, a graphical toolkit that relies on a graphical compiler. Hayaku allows the interaction designer to produce himself the final interactive application. It helps an iterative development cycle. Then, we have worked on the simplification of the description for the final user when she has to create visualizations. We introduced the software FromDaDy to support this creation of large amount of data. Moving the image creation task on the GPU allows us to show a simpler model to the final user. Finally, we have simplified the description of a low algorithm (point based labeling placement algorithm) by using the GPU memory instead of the CPU. This allows us to suppress early complex optimizations and enhance the performances.

Un grand nombre d'activités utilisent des systèmes informatisés s'appuyant sur des représentations graphiques interactives. Les représentations graphiques sont des vecteurs de transmission d'informations, visant à exploiter au mieux la bande passante entre un système et ses utilisateurs. Pour certaines activités, et notamment les activités dites critiques comme l'aéronautique, la qualité des représentations graphiques est primordiale : en effet, si une information graphique est mal perçue par un utilisateur (pilote, contrôleur aérien), les conséquences peuvent être coûteuses, voire dramatiques. La conception et la spécification de ces représentations graphiques sont complexes : les paramètres sont nombreux, les interactions entre paramètres visuels sont difficiles à modéliser et prédire, et leur réglage doit s'appuyer sur des connaissances pluridisciplinaires. Selon nous, les difficultés rencontrées pour gérer ces interactions visuelles proviennent d'un manque de méthodes et d'outils de conception, qui permettraient de répondre aux exigences de plus en plus poussées en matière de rendus graphiques, et de spécifier précisément des besoins parfois mal définis par les cahiers des charges ou exigences. La première partie du travail que nous présentons est basée sur l'étude approfondie des problèmes perceptifs rencontrés sur ces interfaces complexes. Ce travail est réalisé au travers d'études expérimentales traitant de problèmes spécifiques de perception des rendus graphiques. Nous présentons ensuite un travail d'analyse de l'activité à laquelle se livrent les concepteurs d'interfaces critiques. À partir de ces analyses, nous proposons une démarche d'aide à la conception et à la vérification des rendus graphiques répondant aux besoins spécifiques des concepteurs. Cette démarche facilite l'exploration visuelle des solutions, ainsi que la mise en rapport de hiérarchies fonctionnelles liées aux systèmes avec des hiérarchies visuelles perçues par les utilisateurs. Elle supporte une approche de conception itérative, centrée utilisateur et permettant d'accompagner un système sur toute sa durée de vie. Nous proposons pour finir d'instrumenter cette démarche à l'aide de prototypes et d'outils interactifs, dont nous illustrons l'utilisation avec des études de cas.

Cette thèse s'intéresse aux systèmes interactifs critiques et présente une approche permettant de prendre en compte de façon synergique les aspects fiabilité et utilisabilité. En effet, dans le cas des systèmes interactifs critiques, des problèmes d'utilisabilité peuvent réduire les performances de l'opérateur, être source de confusion et de frustration et entraîner des erreurs. De même, des problèmes de fiabilité peuvent entrainer des défaillances lors de l'opération du système. Comme le montrent les études dans le domaine, ces défaillances et ces erreurs sont les principales causes d'incidents ou d'accidents. Pour augmenter la bande passante entre l'utilisateur et le système, les activités d'innovation dans le domaine de l'IHM proposent des nouveaux systèmes d'entrée sortie et des techniques d'interaction plus sophistiquées telles que l'interaction multimodale. Bien qu'un effort important soit entrepris actuellement par le domaine de l'IHM en vue d'appliquer et d'étendre les techniques actuelles d'évaluation d'utilisabilité à ces nouvelles techniques d'interaction, peu de recherches ont été réalisées pour garantir la fiabilité des applications offrant de telles techniques d'interaction. Les processus de conception itératifs contribuent à l'utilisabilité du système par validation successive des prototypes avec les opérateurs mais au détriment de la fiabilité du système final par l'absence de conception globale et structurée. Notre approche est fondée sur une notation formelle et sur un processus de développement mettant en ?uvre cette notation. L'utilisation d'une notation formelle fournit aux différents acteurs de la conception et du développement un langage de communication précis et non ambigu, sur lequel il est possible d'appliquer des méthodes et des techniques de vérification de propriétés. Pour la partie notation, le travail présenté ici est fondé sur le formalisme ICO qui était préexistant à ce travail de thèse. L'apport de ce travail consiste en une approche systématique permettant non seulement de décrire les techniques d'interaction avancées mais aussi de répondre à la fois aux problèmes de fiabilité et d'utilisabilité. De plus, en proposant une architecture évolutive structurant les composants décrits par cette notation et dissociant la conception de techniques d'interaction de la conception du reste du système interactif, nous facilitons les modifications sur les techniques d'interaction ce qui est nécessaire pour être compatible avec les approches itératives mises en avant dans le domaine de l'IHM. Cette approche est exemplifiée à travers différentes études de cas dans le domaine des systèmes interactifs critiques tels que les cockpits et la gestion de satellite.

Les applications Web existantes donnent accès à des ressources (information, contenu, etc.) mais offrent également de plus en plus de services. Si beaucoup d'efforts doivent être consacrés à la fiabilité et à la robustesse de ces applications Web de complexité croissante, l'utilisabilité doit également être assurée, faute de quoi l'utilisateur aura des difficultés d'usage avec l'application. L'évaluation de l'utilisabilité est une tâche complexe qui requiert une connaissance et une expertise en ergonomie logicielle. La plupart des méthodes d'évaluation existantes, bien que maîtrisées par des experts en utilisabilité, sont considérées comme « complexes » et difficiles à mettre en oeuvre pour des non experts. Les recommandations pour l'utilisabilité sont l'expression d'une connaissance en ergonomie qui aide l'évaluation. Toutefois, puisqu'il est nécessaire d'appliquer ces recommandations de manière systématique, leur inspection manuelle peut s'avérer laborieuse, même pour un expert. Afin de ne pas être limité par l'inspection manuelle, des efforts ont été investis dans le développement d'outils supportant la collecte des recommandations et leur organisation, le guidage de l'inspection et le support de l'inspection automatique. Un des avantages à l'utilisation d'outils automatiques pour l'inspection des recommandations est que peu de connaissances en ergonomie sont requises puisque l'expertise est intégrée dans l'outil. En outre, le manque d'experts pour réaliser les évaluations d'utilisabilité et le coût élevé des autres méthodes d'évaluation (par exemple, tests utilisateurs) font que l'inspection automatique des recommandations est une méthode adaptée pour supporter les évaluations fréquentes des applications Web. Cependant, ces outils ne permettent d'évaluer que l?application finale et dans le cas où des erreurs sont détectées, des modifications importantes de l'application peuvent avoir lieu. L'objectif de cette thèse est de proposer une méthode d'évaluation permettant de s'assurer tout au long du processus de conception de la qualité ergonomique des applications Web développées. Sur la base des recommandations existantes, nous avons établi une ontologie qui organise les recommandations autour des éléments d'interface d'une application Web. Cette ontologie forme ainsi un vocabulaire non ambigu et permet d'identifier précisément les éléments à évaluer à chaque étape du processus de conception. En utilisant une approche basée sur modèles nous proposons une méthode d'évaluation qui exploite cette ontologie et les différents artefacts produits tout au long du processus de conception. Cette méthode offre un support à la vérification de la qualité ergonomique pendant tout le cycle de vie de l'application. En outre, ces travaux ont été appliqués et validés à l'échelle industrielle sur une plateforme de développement de téléprocédures adoptant une approche dirigée par les modèles.

Depuis ces dernières années, les institutions gouvernementales profitent du support de l'environnement Web pour publier des informations et pour dématérialiser des procédures administratives. Ces applications dites d'e-Gouvernement (abréviation de « gouvernement électronique ») offrent de nombreux avantages aux citoyens aussi bien qu'aux agents administratifs et aux institutions impliquées : rapidité de transfert d'information, plus de transparence sur le processus, stockage automatique de données sous forme électronique, etc. Toutefois, le développement de ce genre d'applications doit surmonter des difficultés inhérentes aux caractéristiques bien particulières de l'e-Gouvernement. D'une part la dématérialisation des procédures administratives fait intervenir une équipe de conception multidisciplinaire qui a besoin d'outils communs adaptés pour dialoguer. D'autre part, les applications développées doivent être accessibles au plus grand nombre (i.e. tous les citoyens) ce qui nécessite une attention toute particulière à la conception des interfaces utilisateurs. Dans ce contexte, il important d'indiquer que les applications d'e-Gouvernement mises à disposition des citoyens présentent souvent beaucoup de similitudes, ce qui renforce le besoin d'homogénéité des interfaces utilisateurs inter applications. Le travail développé dans cette thèse vise à étudier et à proposer une méthode de conception qui favorise la mise en place de mécanismes d'homogénéisation des interfaces pour des applications d'e-Gouvernement basées sur le Web selon une approche centrée utilisateur. Dans le cadre de ces travaux de thèse, la réflexion a été menée sur la base d'une étude théorique des moyens de mise à disposition des connaissances ergonomiques pour la conception d'interfaces utilisateurs. Cette revue de l'existant a été complétée par une étude ethnographique menée dans une grande entreprise de technologies de l'information dédiée à la conception d'applications d'e-Gouvernement. Suite à ces études, cette thèse présente : a) une méthode de conception basée sur les patrons d'interfaces utilisateurs qui vise au guidage des concepteurs vers l'homogénéité inter applications ; b) un catalogue de patron qui propose des solutions (prouvées rationnellement ou empiriquement) à des problèmes de conception d'interfaces connus et récurrents ; c) un outil permettant la personnalisation guidée de certains patrons d'interface, ceux qui concernent l'enchaînement d'écrans ; et d) une étude sur l'utilisation effective de ces patrons d'interfaces sur le terrain.

Le travail touche le domaine de l'analyse, de la conception et de la validation de systèmes interactifs critiques et résistants eux erreurs. Il concerne plus particulièrement les approches à base de méthodes formelles pour la prise en compte des erreurs humaines.

Il s'agit d'adapter un formalisme de description de systèmes interactifs, les ICO (Interactive Cooperative Objects), à la prise en compte des interfaces multimodales

La plupart des méthodes de conception informatique sont centrées sur la modélisation et la documentation du système issu de la conception laissant de côté les différents chemins (étudiés en détail ou non) ayant conduit à ce système. La conception ainsi obtenue présente quatre défauts majeurs : l'absence de traçabilité de la conception, l'absence d'argumentation des choix effectués (car ces méthodes ne poussent pas les concepteurs à argumenter leurs choix), les difficultés de réutilisation des différents produits de la conception, et enfin le manque de soutien (outils ou démarches) à l'exploration systématique de plusieurs alternatives. La résolution de ces problèmes passe par la mise en œuvre d'approches de conceptions rationalisées à l'intérieur même du processus de développement. La conception rationalisée (design rationale) est une approche qui tend à promouvoir non seulement l'exploration systématique de plusieurs alternatives à un problème donné, mais aussi l'évaluation et l'argumentation de ces différentes alternatives. Cette approche permet également de soutenir la justification systématique des choix effectués par les concepteurs. Diverses notations formelles ou semi formelles ont été proposées dans le but de soutenir ces différentes activités de conception. Les principaux objectifs de ces approches sont d'accroître la qualité finale des systèmes conçus et la réutilisabilité des informations archivées lors d'une conception pour de futures conceptions. Toutefois, les approches de conception rationalisée ne sont pas ou peu mises en œuvre lors de la conception d'un système interactif contrairement à des domaines tels que le génie civil. Nous avons identifié plusieurs raisons à ceci : les outils offerts par le design rationale ne sont pas utilisable dans le cadre d'applications de taille réelle car les notations sont trop génériques (pas spécialisées pour la conception de systèmes interactifs) et les environnements pas adaptés à la saisie et à l'exploitation de larges modèles. Une autre raison, expliquant la faible mise en uvre des approches de conception rationalisée, provient du fait que la conception rationalisée est perçue comme un surcoût à court terme avec des bénéfices peu perceptibles. Cette thèse propose un ensemble de solutions à ces différents points. Dans un premier temps nous proposons une notation TEAM (Traceability, Exploration and Analysis Model), fondée sur la notation QOC (Questions, Options, Criteria) ayant déjà fait l'objet de nombreux travaux dans le domaine. Ayant spécialement été conçu dans l'optique de la conception de systèmes interactifs, TEAM permet d'archiver les informations propres à la conception de systèmes interactifs. TEAM est supporté par l'outil DREAM (Design Rationale Environment for Argumentation and Modelling) qui supporte les activités de saisie, de lecture et de réutilisation de modèles TEAM. Nous avons montré comment intégrer l'approche DREAM/TEAM dans une méthode de conception pour définir comment et quand utiliser le design rationale tout au long du processus de conception. Enfin, l'approche DREAM/TEAM a été confrontée à trois études de cas (conception graphique d'une interface, conception d'un système interactif dans le domaine du contrôle aérien, et intégration de l'évaluation de performance) différentes dans leurs objectifs mais complémentaires. Chacune des études de cas valide un ou plusieurs point précis de la notation TEAM et de l'outil DREAM sur des cas réels d'utilisation.