Model driven design and data integration in semantic web information systems

The Web is quickly evolving in many ways. It has evolved from a Web of documents into a Web of applications in which a growing number of designers offer new and interactive Web applications with people all over the world. However, application design and implementation remain complex, error-prone and laborious. In parallel there is also an evolution from a Web of documents into a Web of `knowledge' as a growing number of data owners are sharing their data sources with a growing audience. This brings the potential new applications for these data sources, including scenarios in which these datasets are reused and integrated with other existing and new data sources. However, the heterogeneity of these data sources in syntax, semantics and structure represents a great challenge for application designers. The Semantic Web is a collection of standards and technologies that offer solutions for at least the syntactic and some structural issues. If offers semantic freedom and flexibility, but this leaves the issue of semantic interoperability. In this thesis we present Hera-S, an evolution of the Model Driven Web Engineering (MDWE) method Hera. MDWEs allow designers to create data centric applications using models instead of programming. Hera-S especially targets Semantic Web sources and provides a flexible method for designing personalized adaptive Web applications. Hera-S defines several models that together define the target Web application. Moreover we implemented a framework called Hydragen, which is able to execute the Hera-S models to run the desired Web application. Hera-S' core is the Application Model (AM) in which the main logic of the application is defined, i.e. defining the groups of data elements that form logical units or subunits, the personalization conditions, and the relationships between the units. Hera-S also uses a so-called Domain Model (DM) that describes the content and its structure. However, this DM is not Hera-S specific, but instead allows any Semantic Web source representation as its DM, as long as its content can be queried by the standardized Semantic Web query language SPARQL. The same holds for the User Model (UM). The UM can be used for personalization conditions, but also as a source of user-related content if necessary. In fact, the difference between DM and UM is conceptual as their implementation within Hydragen is the same. Hera-S also defines a presentation model (PM) which defines presentation details of elements like order and style. In order to help designers with building their Web applications we have introduced a toolset, Hera Studio, which allows to build the different models graphically. Hera Studio also provides some additional functionality like model checking and deployment of the models in Hydragen. Both Hera-S and its implementation Hydragen are designed to be flexible regarding the user of models. In order to achieve this Hydragen is a stateless engine that queries for relevant information from the models at every page request. This allows the models and data to be changed in the datastore during runtime. We show that one way to exploit this flexibility is by applying aspect-orientation to the AM. Aspect-orientation allows us to dynamically inject functionality that pervades the entire application. Another way to exploit Hera-S' flexibility is in reusing specialized components, e.g. for presentation generation. We present a configuration of Hydragen in which we replace our native presentation generation functionality by the AMACONT engine. AMACONT provides more extensive multi-level presentation generation and adaptation capabilities as well aspect-orientation and a form of semantic based adaptation. Hera-S was designed to allow the (re-)use of any (Semantic) Web datasource. It even opens up the possibility for data integration at the back end, by using an extendible storage layer in our database of choice Sesame. However, even though theoretically possible it still leaves much of the actual data integration issue. As this is a recurring issue in many domains, a broader challenge than for Hera-S design only, we decided to look at this issue in isolation. We present a framework called Relco which provides a language to express data transformation operations as well as a collection of techniques that can be used to (semi-)automatically find relationships between concepts in different ontologies. This is done with a combination of syntactic, semantic and collaboration techniques, which together provide strong clues for which concepts are most likely related. In order to prove the applicability of Relco we explore five application scenarios in different domains for which data integration is a central aspect. This includes a cultural heritage portal, Explorer, for which data from several datasources was integrated and was made available by a mapview, a timeline and a graph view. Explorer also allows users to provide metadata for objects via a tagging mechanism. Another application is SenSee: an electronic TV-guide and recommender. TV-guide data was integrated and enriched with semantically structured data from several sources. Recommendations are computed by exploiting the underlying semantic structure. ViTa was a project in which several techniques for tagging and searching educational videos were evaluated. This includes scenarios in which user tags are related with an ontology, or other tags, using the Relco framework. The MobiLife project targeted the facilitation of a new generation of mobile applications that would use context-based personalization. This can be done using a context-based user profiling platform that can also be used for user model data exchange between mobile applications using technologies like Relco. The final application scenario that is shown is from the GRAPPLE project which targeted the integration of adaptive technology into current learning management systems. A large part of this integration is achieved by using a user modeling component framework in which any application can store user model information, but which can also be used for the exchange of user model data

Agile managing of web requirements with WebSpec

Web application development is a complex and time consuming process that involves di erent stakeholders (ranging from customers to developers); these applications have some unique characteristics like navigational access to information, sophisticated interaction features, etc. However, there have been few proposals to represent those requirements that are speci c to Web applications. Consequently, validation of requirements (e.g. in acceptance tests) is usually informal, and as a result troublesome. To overcome these problems, this PhD Thesis proposes WebSpec, a domain speci c language for specifying the most relevant and characteristic requirements of Web applications: those involving interaction and navigation. We describe WebSpec diagrams, discussing their abstraction and expressive power. As part of this work, we have created a test driven model based approach called WebTDD that gives a good framework for the language. Using the language with this approach we have test several of its features such as automatic test generation, management of changes in requirements, and improving the understanding of the diagrams through application simulation. This PhD Thesis is composed of a set of published and submitted papers. In order to write this PhD Thesis as a collection of papers, several requirements must be taken into account as stated by the University of Alicante. With regard to the content of the PhD Thesis, it must speci cally include a summary which is devoted to the description of initial hypotheses, research objectives, and the collection of publications itself, thus justifying its coherence. It should be underlined that this summary of the PhD Thesis must also include research results and nal conclusions. This summary corresponds to part I of this PhD Thesis (chapter 1 has been written in Spanish while chapter 2 is in English). This work has been partially supported by the following projects: MANTRA (GV/2011/035) from Valencia Ministry, MANTRA (GRE09-17) from the University of Alicante and by the MESOLAP (TIN2010-14860) project from the Spanish Ministry of Education and Science.Este trabajo ha sido parcialmente financiado por los siguientes proyectos: Mantra (GV/2011/035), Ministerio de Valencia, MANTRA (GRE09-17) de la Universidad de Alicante y por el MESOLAP (TIN2010-14860) proyecto del Ministerio de Educación y Ciencia de España.Facultad de Informátic

Development of a personalization model for web applications in a context of model-driven development

ABSTRACT: This dissertation develops and validates a maintainable approach to improve the modifiability of personalized web applications and to reduce the technical complexity to integrate personalization strategies in a short time in a business environment. The Software Reference Architecture to face the maintainability problem was proposed and the MAMPA framework (Model-driven Approach to enhance the Modifiability of Personalized Web Applications) was implemented

Semantic discovery and reuse of business process patterns

Patterns currently play an important role in modern information systems (IS) development and their use has mainly been restricted to the design and implementation phases of the development lifecycle. Given the increasing significance of business modelling in IS development, patterns have the potential of providing a viable solution for promoting reusability of recurrent generalized models in the very early stages of development. As a statement of research-in-progress this paper focuses on business process patterns and proposes an initial methodological framework for the discovery and reuse of business process patterns within the IS development lifecycle. The framework borrows ideas from the domain engineering literature and proposes the use of semantics to drive both the discovery of patterns as well as their reuse

THE IMPACT OF LEARNING STYLES AND CULTURAL BACKGROUND ON USERS’ EXPERIENCE OF WEBSITES

Many different types of people now use websites for many sources of information. Nevertheless, the diversity and complexity of the online information available on websites and the desire to make websites provide all information for all users, regardless their interest, ability or characteristics, means that websites can be overwhelming to users. Museum websites are a case in point, trying to provide information to a great diversity of users. For these reasons, there have been numerous efforts to individualize user experiences in websites. These efforts have been based on users’ individual or group differences such as their goals, interests, preferences, knowledge, backgrounds, demographic characteristics, experience, learning styles, and culture. This programme of research investigates whether learning styles as an individual difference and cultural background as a group difference can affect web users’ experience, performance and perceived usability by conducting a card sort study, an interview study and an ecologically valid study of users’ experience with museum websites. To investigate learning styles, the Felder-Silverman Learning Style Model was used with its associated Felder-Solomon Index of Learning Styles (ILS). The ILS was developed in English, making it unsuitable for Turkish learners, one of the target cultural groups for this research programme. Therefore, the ILS was translated into Turkish and adequate reliability and validity established by administering it twice over a four-week interval to 63 undergraduate students in Turkey. Henceforth, the Turkish version of the ILS will be referred as the Turkish Index of Learning Styles (T)ILS. The aim of the card sort study was to investigate user understandings of the organization of the museum and news websites and to reveal learning styles and cultural differences between participants’ categorizations and mental models of the information architectures. The study was conducted in UK and Turkey with 214 and 90 participants, respectively. Analysis of the data showed that participants have mental models that differ substantially from the typical websites in these domains. In addition, interesting and meaningful differences were found between participants with different learning styles profiles and among British, Chinese, Indian and Turkish participants. This study also made a methodological contribution, showing that the card sort method can be used to show learning styles and cultural differences. The aim of the interview study was to investigate the perceptions of museum personnel concerning the adaptation of websites in relation to both learning styles and cultural differences among visitors and to investigate whether they were interested in these issues. Five developers from Turkey and five developers from UK and USA were interviewed and content analysis was used to analyze their responses. The study showed that almost none of the interviewees were aware of the concept of learning styles, but the majority were very interested when they were told about it. Furthermore, a majority of interviewees thought learning styles had potential to make their websites more appealing to a wider range of visitors. Lastly, most interviewees were interested in the idea of dealing with cultural differences in other ways than mere translation of texts. The final study investigated how learning styles and cultural differences affect users’ experience, performance and perception of the usability of two museum websites. It was administered in the UK with an international sample of 210 participants. Participants were asked to perform a number of tasks on these websites, the tasking being carefully chosen to direct participants to aspects of the websites that would suit particular learning styles. This study showed significant differences among users depending on their learning styles and cultural background. This study also makes an important methodological contribution in that moves away from the paradigm of trying to manipulate online materials to match or clash with users’ learning styles or other preferences. The results of this research programme will be important for developers of museum and similar websites who want to take the advantage of developing supportive websites by focusing on users’ learning styles and cultural differences

Context-Aware and Adaptable eLearning Systems

The full text file attached to this record contains a copy of the thesis without the authors publications attached. The list of publications that are attached to the complete thesis can be found on pages 6-7 in the thesis.This thesis proposed solutions to some shortcomings to current eLearning architectures. The proposed DeLC architecture supports context-aware and adaptable provision of eLearning services and electronic content. The architecture is fully distributed and integrates service-oriented development with agent technology. Central to this architecture is that a node is our unit of computation (known as eLearning node) which can have purely service-oriented architecture, agent-oriented architecture or mixed architecture. Three eLeaerning Nodes have been implemented in order to demonstrate the vitality of the DeLC concept. The Mobile eLearning Node uses a three-level communication network, called InfoStations network, supporting mobile service provision. The services, displayed on this node, are to be aware of its context, gather required learning material and adapted to the learner request. This is supported trough a multi-layered hybrid (service- and agent-oriented) architecture whose kernel is implemented as middleware. For testing of the middleware a simulation environment has been developed. In addition, the DeLC development approach is proposed. The second eLearning node has been implemented as Education Portal. The architecture of this node is poorly service-oriented and it adopts a client-server architecture. In the education portal, there are incorporated education services and system services, called engines. The electronic content is kept in Digital Libraries. Furthermore, in order to facilitate content creators in DeLC, the environment Selbo2 was developed. The environment allows for creating new content, editing available content, as well as generating educational units out of preexisting standardized elements. In the last two years, the portal is used in actual education at the Faculty of Mathematics and Informatics, University of Plovdiv. The third eLearning node, known as Agent Village, exhibits a purely agent-oriented architecture. The purpose of this node is to provide intelligent assistance to the services deployed on the Education Pportal. Currently, two kinds of assistants are implemented in the node - eTesting Assistants and Refactoring eLearning Environment (ReLE). A more complex architecture, known as Education Cluster, is presented in this thesis as well. The Education Cluster incorporates two eLearning nodes, namely the Education Portal and the Agent Village. eLearning services and intelligent agents interact in the cluster