Ein zentraler Vorteil des Webs gegenüber herkömmlichen Anwendungsplattformen stellt sein großes Potential dar, Aufgaben über Organisationsgrenzen hinweg zu unterstützen. Derzeit lassen sich Tendenzen zu einer Klasse von föderativen Web-Anwendungen beobachten, die dieses Potential verstärkt ausschöpfen. Eine besondere Herausforderung bei ihrer Entwicklung ergibt sich durch die Ausrichtung der Zugangskontrolle auf zugreifende Benutzer, deren Identitäten von Partnerorganisationen verwaltet werden. Die Arbeit erweitert den Stand der Technik im Bereich Web Engineering um Werkzeuge, Modelle, Methoden und Prozesse zum gezielten Unterstützen der Evolution föderativer Systeme. Sie umfasst einen Katalog aus Entwurfsbausteinen für föderative Infrastrukturen, eine Modellierungssprache zur Planung der föderativen Architektur sowie eine Methode zur Integration föderativ geschützter Informationsräume in Web-Anwendungen. / A central advantage of the Web over traditional application plattforms lies in its great potential for supporting tasks beyond organizational boundaries. Presently, a trend towards a new class of federated Web applications can be observed that exploit this potential to a high degree. The development of such applications is particularly challenged by the need for controlling accesses of users whose identities are managed by partner organizations. This work extends the state of the art in the area of Web Engineering with tools, models, methods and processes for supporting the evolution of federated systems. It comprises a catalogue of design building blocks for federated infrastructures, a modeling language for planning federated architectures as well as a method for integrating information spaces of applications that are subject to federated access control.

When building enterprise applications that need to be accessed through a variety of client devices, developers usually strive to implement most of the business logic device-independently while using a web browser to display the user interface. However, when those web-based front-ends shall be rendered on different devices, their differing I/O capabilities may require device-specific interaction patterns that still need to be specified and implemented efficiently. We present an approach for specifying the dialog flows in multi-channel web interfaces with very low redundancy and introduce a framework that controls web interfaces’ device-specific dialog flows according to those specifications, while keeping the enterprise application logic completely device-independent.

When considering the addition of a mobile presentation channel to an existing web-based application, a key question that has to be answered even before development begins is how the mobile channel's characteristics will impact the user experience and the cost of using the application. If either of these factors is outside acceptable limits, economical considerations may forbid adding the channels, even if it would be feasible from a purely technical perspective. Both of these factors depend considerably on two metrics: The time required to transmit data over the mobile network, and the volume transmitted. The PETTICOAT method presented in this paper uses the dialog flow model and web server log files of an existing application to identify typical interaction sequences and to compile volume statistics, which are then run through a tool that simulates the volume and time that would be incurred by executing the interaction sequences on a mobile channel. From the simulated volume and time data, we can then calculate the cost of accessing the application on a mobile channel, and derive suitable approaches for optimizing cost and response times.

When considering the addition of a mobile presentation channel to an existing web-based application, a key question that has to be answered even before development begins is how the mobile channel’s characteristics will impact the user experience and the cost of using the application. If either of these factors is outside acceptable limits, economical considerations may forbid adding the channels, even if it would be feasible from a purely technical perspective. Both of these factors depend considerably on two metrics: The time required to transmit data over the mobile network, and the volume transmitted. The PETTICOAT method presented in this paper uses the dialog flow model and web server log files of an existing application to identify typical interaction sequences and to compile volume statistics, which are then run through a tool that simulates the volume and time that would be incurred by executing the interaction sequences on a mobile channel. From the simulated volume and time data, we can then calculate the cost of accessing the application on a mobile channel.

Les développeurs d'applications Web ne sont pas tous des experts. Même s'ils utilisent des méthodes telles que UWE (UML web engineering) et les outils CASE, ils ne sont pas toujours capables de prendre de bonnes décisions concernant le contenu de l'application web, le schéma de navigation et / ou la présentation des informations. La littérature leur fournit de nombreuses lignes directrices (guidelines) pour ces tâches. Cependant, ces connaissances sont disséminées dans de nombreuses sources et non structurées. Dans cette dissertation, nous capitalisons sur les connaissances offertes par ces lignes directrices. Notre contribution est triple: (i) nous proposons un méta-modèle permettant une représentation riche de ces lignes directrices, (ii) nous proposons une grammaire permettant la description des lignes directrices existantes, (iii) sur la base de cette grammaire, nous développons un outil de gestion des lignes directrices . Nous enrichissons la méthode UWE avec cette base de connaissances menant à une approche basée sur la qualité. Ainsi, notre outil enrichit les prototypes existants d'ingénierie logicielle assistée par ordinateur basés sur UWE avec des conseils ad hoc. / Web application developers are not all experts. Even if they use methods such as UWE (UML web engineering) and CASE tools, they are not always able to make good decisions regarding the content of the web application, the navigation schema, and/or the presentation of information. Literature provides them with many guidelines for these tasks. However this knowledge is disseminated in many sources and not structured. In this dissertation, we perform a knowledge capitalization of all these guidelines. The contribution is threefold: (i) we propose a meta-model allowing a rich representation of these guidelines, (ii) we propose a grammar enabling the description of existing guidelines, (iii) based on this grammar, we developed a guideline management tool. We enrich the UWE method with this knowledge base leading to a quality based approach. Thus, our tool enriches existing UWE-based Computer Aided Software Engineering prototypes with ad hoc guidance.

Wissenschaftliche Schriftenreihe, die Dissertationen der Professur Verteilte und selbstorganisierende Rechnersysteme beinhaltet. / Scientific series containing dissertations of the Professorship Distributed and Self-Organizing Systems.

The integration of mobile and sensor technologies, and the design and implementation of different web-enabled visualizations to support inquiry learning in different educational scenarios encompass the main research efforts carried out in this thesis. These challenges are addressed from the perspectives of mobile and web engineering, visualization and technology-enhanced learning (TEL). Thus, the main research question investigated in this thesis relates to the identification of the main features that can guide the design and implementation of web and mobile applications to support inquiry learning in different contexts. This thesis consists of a collection of four publications that describe the research efforts conducted during a period of three years in relation to the Learning Ecology through Science with Global Outcomes (LETS GO) research project. The research questions investigated and the implemented technological solutions reported in these publications are closely related to the main goals and challenges of this thesis. The design and implementation of the proposed software system was guided, deployed and refined having the following aspects in mind: (1) System Requirements and Architectural Design, (2) System Implementation and Deployment, and (3) System Assessment and Web Usability Testing. During the three years of development efforts, three software prototypes were implemented utilizing service-oriented approaches. These efforts have been tested with more than 200 users in connection to several trials that took place during this period. The user trials allowed testing the software application throughout three development iterations on authentic settings, while new requirements continuously emerged in these activities. This process made it possible to verify that user requirements were adequately addressed while satisfying their needs. The outcomes of these activities led to the design and implementation of a system architecture that relies on service-oriented approaches and open standards. The main outcomes of this thesis are presented in the form of Architectural Concepts, as they can be used to guide the design and implementation of web and mobile applications to support inquiry learning. The idea behind architectural concepts is to provide a set of tools for supporting the overall life cycle of a software development process, such as requirements, design, implementation, deployment and testing while coping with rapid changes of technological implementations. Some of the architectural concepts identified in this thesis correspond well with the kind of support that inquiry-learning activities require. They provide solid foundations in terms of possibilities to tackle the requirements for supporting inquiry learning in a flexible manner.

A literatura relata que a produção de aplicações Web apresenta problemas de baixa qualidade nas aplicações desenvolvidas, não-cumprimento de prazo e orçamento, desenvolvimento ad hoc, caótico e desestruturado. Acrescente-se que diferentes disciplinas e áreas do conhecimento, com abordagens e metodologias próprias, estão envolvidas com esse tipo de produção. Verifica-se que aplicações Web são desenvolvidas por profissionais de Software, Design, Comunicação e Mídia, entre outros. Uma área do conhecimento denominada Engenharia Web foi criada para enfocar estas questões, entretanto, ainda não está consolidada. O presente trabalho tem como objetivo apresentar diretrizes para a definição do processo de produção de aplicações Web, a partir de uma abordagem sistêmica deste, na qual as diferentes disciplinas, papéis e atividades são correlacionados na fase de concepção do projeto. Utiliza-se como método de pesquisa a revisão bibliográfica e, a partir desta, estudos de caso e pesquisa-ação para a formação de um modelo teórico. Este abstrai os aspectos fundamentais das principais disciplinas envolvidas na produção de aplicações Web e permite a instanciação de um processo adequado às particularidades de diferentes projetos. O trabalho identifica um espaço de projeto formado pelas dimensões Forma, Função, Informação e Tecnologia, relacionadas, por sua vez, às principais disciplinas envolvidas na produção de aplicações Web: Design, Engenharia de Software, Comunicação e Mídia. Conclui-se que, em função do(s) padrão(ões) de projeto utilizado(s), existe um enfoque mais adequado para o processo de produção, orientado sobre uma ou mais dimensões do espaço de projeto, bem como um papel centralizador, focado em uma disciplina, que permite o projeto evoluir mais rapidamente a um nível esperado de qualidade. / The literature relates that Web applications production presents problems like: low quality; ad-hoc, chaotic and unstructured process; budget and time overlap. Moreover, different disciplines and knowledge areas, with particular approaches and methodologies, contribute with this kind of production. It is verified that Web applications are developed by professionals of Software, Design Communication & Media, and others. A particular knowledge area called Web Engineering was developed to focus these questions; however, it is not consolidated yet. This work has as objective to present guidelines to the definition of the Web applications production process, directed by a systemic approach to this process, on that the different disciplines, roles and activities are correlated, in the conception phase. The research method utilizes bibliographic review and than, cases studies and action-research to create a theoretical model. This model abstracts the fundamental aspects of the involved disciplines in the Web applications production and enables a process instantiation, adequate to the particularities of different projects. The work identifies a design space formed by the dimensions Form, Function, Information and Technology, related to the main disciplines involved in Web applications production: Design (styling), Software Engineering and Communication & Media. It concludes that, guided by design patterns utilized, a best fit production process approach can be found, oriented on one or more dimensions of the design space, as well as a centralizer role, focused in a discipline. This approach allows to the project a quick evolution to the expected quality level.

Com a popularização da Web 2.0 e RIA - Rich Internet Applications, as aplicações web cada vez mais utilizam-se da linguagem JavaScript, para implementar recursos de interação sofisticados e complexos na plataforma da Web, visando atrair os usuários com experiências que agradem e atendam suas expectativas. Uma vez que esses recursos de RIA, muitas vezes, fornecem feedback visual de mudanças realizadas na interface, usuários que interagem com a Web por meio de Tecnologias Assistivas, como leitores de tela, não são capazes de identificar e interagir corretamente com os componentes de interface. Assim, a WAI - Web Accessibility Initiative propôs a especificação ARIA - Accessible Rich Internet Applications que determina um conjunto de propriedades que atribuem semântica aos elementos de um componente de interface (Widget), permitindo que as Tecnologias Assistivas identifiquem previamente o comportamento dos componentes de interface e informem o usuário sobre as alterações que possam ser realizadas na estrutura da página web. Nesse contexto, esta tese teve como objetivo elaborar estratégias de avaliação automática dos requisitos de acessibilidade da especificação ARIA. Foram elaboradas três diferentes abordagens para analisar os requisitos da especificação ARIA, utilizando a metodologia de pesquisa-ação com a condução de três ciclos das atividades de planejar, agir, descrever e avaliar. As abordagens foram desenvolvidas com base em Testes de Aceitação e verificações de características tecnológicas das aplicações web, considerando especificamente o modelo de interação de usuários deficientes visuais que utilizam leitores de tela. Cada uma das abordagens foi validada separadamente e os resultados apresentam tendências de que as estratégias são capazes de avaliar corretamente o comportamento esperado de uma aplicação rica de Internet acessível, segundo as recomendações ARIA para usuÁ¡rios deficientes visuais. As abordagens também apresentaram como contribuições: a inclusão do modelo de interação do usuário no processo de avaliação e levantamentos sobre os níveis de conformidade de aplicações web e bibliotecas JavaScript com a especificação ARIA. Os resultados obtidos a partir das abordagens propostas nesta tese contribuem para o processo de Engenharia Web de aplicações ricas de Internet acessíveis / With the increased popularity of the Web 2.0 and RIA - Rich Internet Applications, web applications rely more and more in JavaScript to implement richer and more complex interaction mechanisms in the Web platform. Since these mechanisms, frequently, generate dynamic updates to the DOM - Document Object Model structure of a webpage and require visual perception of users to notify them about these changes in the interface, users that interact with the Web through usage of Assistive Technologies such as a screen reader are not capable of correctly identifying and interacting with the interface components built with these technologies - the widgets. In this context, the WAI - Web Accessibility Initiative created the ARIA - Accessible Rich Internet Applications specification which describes the use of properties that add semantics to elements that compose a widget, allowing Assistive Technology to priorly identify the behavior of a widget and inform the user about changes that might be made to the DOM structure of the webpage. This thesis goal was to elaborate automatic evaluation strategies for accessibility requirements of the ARIA specification. Three evaluation strategies were elaborated following the research-action methodology with the conduction of three cycles of the activities of planning, acting, describing and evaluating. The strategies were implemented based in Acceptance Tests and verifications on specific details of the technology that compose web applications, considering specifically blind users interaction patterns through the use of screen readers. Each strategy was separately validated and the results show tendencies that the strategies were capable of correctly evaluating the behavior of web applications, considering their conformance with ARIA recommendations for blind users. The development and validation of the evaluation strategies also presented contributions by: including user interaction models in the automatic evaluation approaches and presenting a survey on web applications and JavaScript toolkits conformance rates with the ARIA specification. Thus contributing to the Web Engineering process of ARIA

This thesis presents an extensive survey of 100,000 websites as the basis for understanding the deployment of cookies across the Internet. The survey indicates cookie deployment on the Internet is approaching universal levels. The survey identifies the presence of P3P policies and dynamic web technologies as major predictors of cookie usage, and a number of significant relationships are established between the origin of the web application and cookie deployment. Large associations are identified between third-party persistent cookie usage and a countrys e-business environment. Cookie collection testing (CCT), a strategy for testing web applications, is presented. Cookies maintained in a browser are explored in light of anti random testing techniques, culminating in the definition of seeding vectors as the basis for a scalable test suite. Essentially CCT seeks to verify web application robustness against the modificationintentional or otherwiseof an application's internal state variables. Automation of CCT is outlined through the definition of test oracles and evaluation criterion. Evolutionary adaptive random (eAR) testing is proposed for application to the cookie collection testing strategy. A simulation study is undertaken to evaluate eAR against the current state-of-the-art in adaptive random testingfixed size candidate set, restricted random testing, quasi-random testing, and random testing. eAR is demonstrated to be superior to the other techniques for block pattern simulations. For fault patterns of increased complexity, eAR is shown to be comparable to the other methods. An empirical investigation of CCT is undertaken. CCT is demonstrated to reveal defects within web applications, and is found to have a substantial fault-triggering rate. Furthermore, CCT is demonstrated to interact with the underlying application, not just the technological platform upon which an application is implemented. Both seeding and generated vectors are found to be useful in triggering defects. A synergetic relationship is found to exist between the seeding and generated vectors with respect to distinct fault detection. Finally, a large significant relationship is established between structural and content similarity measures of web application responses, with a composite of the two similarity measures observed to be superior in the detection of faults. / Software Engineering and Intelligent Systems