A expansão das tecnologias de comunicação e informação apoiadas pela internet trazem benefícios crescentes à sociedade. As redes sociais geolocalizadas, televisores que fazem uso da internet e avançados telefones celulares ganham popularidade em conjunto ao aumento da disponibilidade de acesso à internet. A utilização de tais meios para o compartilhamento de informações possibilita a construção de ambientes ricos em informação e conhecimento. Incorporar tais benefícios a ambientes educacionais, propondo métodos que façam uso da riqueza de informações inerentes a tais domínios, provendo a sugestão de conteúdos educacionais é o foco do presente trabalho. Para isto, é apresentado o arcabouço teórico das áreas de Sistemas de Recomendação, Ontologias, Metadados Educacionais e Web Semântica. Revisar os conceitos e o estado da arte de tais áreas conduz a uma análise crítica das mesmas, bem como, ao conjunto de práticas para a descrição de ontologias, que atuem como núcleo de conhecimento, para aplicações educacionais voltadas a recomendação de objetos de aprendizagem. Em conjunto, é também apresentada uma alternativa para que os desenvolvedores de sistemas educacionais possam repensar a maneira como estes estão sendo desenvolvidos, abrindo possibilidades para a agregação de serviços baseados na web semântica que facilitem integrações, filtros e compartilhamentos de informações. Os resultados obtidos através do método de representação de conhecimento que foi proposto neste trabalho, prevê a descrição de objetos de aprendizagem, perfis de usuários, como indivíduos de ontologias, bem como, perfis de aplicação que possibilitam raciocínio lógico visando auxiliar a sistemas de recomendação, e também uma proposta para a migração dos atuais repositórios de conteúdos educacionais para repositórios compatíveis com triplas, também compõe o presente trabalho. / It is a fact that the expansion of the communication and information technologies supported by the Internet brought growing benefits to the society. Geo-localized social networks, televisions that make use of the Internet and smartphones became popular with the wide spread of the Internet access. Information sharing among those devices took information and knowledge sharing at a new level. Incorporate such benefits to educational environments, especially when dealing with content suggestion it is the main focus of this work. To cope with this, we present a theoretical study over the areas of recommender systems, ontologies, educational metadata and semantic web. The study of such concepts and their following state of the art lead to a critical analyses, as also, to a set of practices to describe ontologies that can act as the knowledge core of learning object recommendation. Parallel to that, it is also presented an alternative for educational systems designers to reconsider the way that they are being developed, allowing the connection of a network of services, based on semantic web techniques, to provide knowledge filtering and sharing. The results present a set of practices that allow the description of learning objects and user profiles as ontology individuals, practices to build application profiles that allow reasoning over them, as also an alternative to migrate the current learning object repositories to a triple store.

A expansão das tecnologias de comunicação e informação apoiadas pela internet trazem benefícios crescentes à sociedade. As redes sociais geolocalizadas, televisores que fazem uso da internet e avançados telefones celulares ganham popularidade em conjunto ao aumento da disponibilidade de acesso à internet. A utilização de tais meios para o compartilhamento de informações possibilita a construção de ambientes ricos em informação e conhecimento. Incorporar tais benefícios a ambientes educacionais, propondo métodos que façam uso da riqueza de informações inerentes a tais domínios, provendo a sugestão de conteúdos educacionais é o foco do presente trabalho. Para isto, é apresentado o arcabouço teórico das áreas de Sistemas de Recomendação, Ontologias, Metadados Educacionais e Web Semântica. Revisar os conceitos e o estado da arte de tais áreas conduz a uma análise crítica das mesmas, bem como, ao conjunto de práticas para a descrição de ontologias, que atuem como núcleo de conhecimento, para aplicações educacionais voltadas a recomendação de objetos de aprendizagem. Em conjunto, é também apresentada uma alternativa para que os desenvolvedores de sistemas educacionais possam repensar a maneira como estes estão sendo desenvolvidos, abrindo possibilidades para a agregação de serviços baseados na web semântica que facilitem integrações, filtros e compartilhamentos de informações. Os resultados obtidos através do método de representação de conhecimento que foi proposto neste trabalho, prevê a descrição de objetos de aprendizagem, perfis de usuários, como indivíduos de ontologias, bem como, perfis de aplicação que possibilitam raciocínio lógico visando auxiliar a sistemas de recomendação, e também uma proposta para a migração dos atuais repositórios de conteúdos educacionais para repositórios compatíveis com triplas, também compõe o presente trabalho. / It is a fact that the expansion of the communication and information technologies supported by the Internet brought growing benefits to the society. Geo-localized social networks, televisions that make use of the Internet and smartphones became popular with the wide spread of the Internet access. Information sharing among those devices took information and knowledge sharing at a new level. Incorporate such benefits to educational environments, especially when dealing with content suggestion it is the main focus of this work. To cope with this, we present a theoretical study over the areas of recommender systems, ontologies, educational metadata and semantic web. The study of such concepts and their following state of the art lead to a critical analyses, as also, to a set of practices to describe ontologies that can act as the knowledge core of learning object recommendation. Parallel to that, it is also presented an alternative for educational systems designers to reconsider the way that they are being developed, allowing the connection of a network of services, based on semantic web techniques, to provide knowledge filtering and sharing. The results present a set of practices that allow the description of learning objects and user profiles as ontology individuals, practices to build application profiles that allow reasoning over them, as also an alternative to migrate the current learning object repositories to a triple store.

A expansão das tecnologias de comunicação e informação apoiadas pela internet trazem benefícios crescentes à sociedade. As redes sociais geolocalizadas, televisores que fazem uso da internet e avançados telefones celulares ganham popularidade em conjunto ao aumento da disponibilidade de acesso à internet. A utilização de tais meios para o compartilhamento de informações possibilita a construção de ambientes ricos em informação e conhecimento. Incorporar tais benefícios a ambientes educacionais, propondo métodos que façam uso da riqueza de informações inerentes a tais domínios, provendo a sugestão de conteúdos educacionais é o foco do presente trabalho. Para isto, é apresentado o arcabouço teórico das áreas de Sistemas de Recomendação, Ontologias, Metadados Educacionais e Web Semântica. Revisar os conceitos e o estado da arte de tais áreas conduz a uma análise crítica das mesmas, bem como, ao conjunto de práticas para a descrição de ontologias, que atuem como núcleo de conhecimento, para aplicações educacionais voltadas a recomendação de objetos de aprendizagem. Em conjunto, é também apresentada uma alternativa para que os desenvolvedores de sistemas educacionais possam repensar a maneira como estes estão sendo desenvolvidos, abrindo possibilidades para a agregação de serviços baseados na web semântica que facilitem integrações, filtros e compartilhamentos de informações. Os resultados obtidos através do método de representação de conhecimento que foi proposto neste trabalho, prevê a descrição de objetos de aprendizagem, perfis de usuários, como indivíduos de ontologias, bem como, perfis de aplicação que possibilitam raciocínio lógico visando auxiliar a sistemas de recomendação, e também uma proposta para a migração dos atuais repositórios de conteúdos educacionais para repositórios compatíveis com triplas, também compõe o presente trabalho. / It is a fact that the expansion of the communication and information technologies supported by the Internet brought growing benefits to the society. Geo-localized social networks, televisions that make use of the Internet and smartphones became popular with the wide spread of the Internet access. Information sharing among those devices took information and knowledge sharing at a new level. Incorporate such benefits to educational environments, especially when dealing with content suggestion it is the main focus of this work. To cope with this, we present a theoretical study over the areas of recommender systems, ontologies, educational metadata and semantic web. The study of such concepts and their following state of the art lead to a critical analyses, as also, to a set of practices to describe ontologies that can act as the knowledge core of learning object recommendation. Parallel to that, it is also presented an alternative for educational systems designers to reconsider the way that they are being developed, allowing the connection of a network of services, based on semantic web techniques, to provide knowledge filtering and sharing. The results present a set of practices that allow the description of learning objects and user profiles as ontology individuals, practices to build application profiles that allow reasoning over them, as also an alternative to migrate the current learning object repositories to a triple store.

Η ραγδαία ανάπτυξη του Παγκόσμιου Ιστού τα τελευταία χρόνια έχει προκαλέσει την αύξηση του εκπαιδευτικού υλικού που είναι διαθέσιμο σε ηλεκτρονική μορφή, με αποτέλεσμα η αναζήτηση και η εύρεση των ψηφιακών εκπαιδευτικών υλικών να γίνεται όλο και πιο δύσκολη. Για αυτό το λόγο τα ψηφιακά εκπαιδευτικά αντικείμενα, ή αλλιώς Μαθησιακά Αντικείμενα (Learning Objects) πρέπει να περιγράφονται με τη χρήση εκπαιδευτικών μεταδεδομένων έτσι ώστε να διευκολύνονται οι λειτουργίες της εύρεσης, ανάκτησης, κατηγοριοποίησης και επαναχρησιμοποίησης των αντικειμένων. Τα τελευταία χρόνια έχουν δημιουργηθεί αρκετά αποθέματα για την αποθήκευση ψηφιακών εκπαιδευτικών αντικειμένων, όπως είναι το DSpace, το EPrints και το Fedora. Τα ψηφιακά αποθέματα κάνουν χρήση μεταδεδομένων για τα ψηφιακά αντικείμενα που αποθηκεύονται στο σύστημά τους. Συχνά όμως παρατηρείται ότι ενώ η κύρια χρήση των αποθεμάτων είναι για εκπαιδευτικούς σκοπούς, δεν δίνεται η δυνατότητα να εμπλουτίζονται τα εκπαιδευτικά αντικείμενα που αποθηκεύονται στα αποθέματα με μεταδεδομένα εκπαιδευτικού τύπου. Κατά συνέπεια, ο κύριος στόχος της διπλωματικής εργασίας είναι να μελετήσει τα διαθέσιμα πρότυπα εκπαιδευτικών μεταδεδομένων και να επεκτείνει τα υπάρχοντα σύνολα μεταδεδομένων των ψηφιακών αποθεμάτων ώστε να συμπεριλαμβάνουν και μεταδεδομένα εκπαιδευτικού σκοπού. Για να επιβεβαιωθούν τα αποτελέσματα της συγκεκριμένης μελέτη έγινε εφαρμογή της σε ένα πραγματικό εκπαιδευτικό απόθεμα που αναπτύχθηκε στα πλαίσια του ΕΠΕΑΕΚ ΙΙ για το Πανεπιστήμιο Πατρών. Βασικό χαρακτηριστικό των εκπαιδευτικών αποθεμάτων είναι και η διαλειτουργικότητα με άλλα συστήματα. Η διαλειτουργικότητα εξασφαλίζει τη συνεργασία του συστήματος με άλλα αποθέματα επιτρέποντας τη συγκομιδή και αξιοποίηση των ψηφιακών αντικειμένων και από άλλα αποθέματα. Για το λόγο αυτό μελετάται το πώς μπορεί να επιτευχθεί η διαλειτουργικότητα ενός συστήματος ώστε να αξιοποιούνται και τα εκπαιδευτικά μεταδεδομένα του αποθέματος, μέσω της υπηρεσίας ΟΑΙ-PMH, που υποστηρίζεται από τα περισσότερα αποθέματα, αλλά και μέσω της καινούριας υπηρεσίας OAI-ORE. Η υλοποίηση της διαλειτουργικότητας στα πλαίσια της συγκεκριμένης εργασίας επικεντρώνεται στο σύστημα DSpace. Ο Σημαντικός Ιστός (Semantic Web) αποτελεί την εξέλιξη του Παγκόσμιου Ιστού. Στον Σημαντικό Ιστό οι πληροφορίες περιγράφονται από δεδομένα αποκτώντας συγκεκριμένη σημασία και δίνοντας έτσι τη δυνατότητα στις μηχανές να επεξεργαστούν δεδομένα που μέχρι σήμερα ήταν κατανοητά μόνο από τους ανθρώπους. Έτσι, γίνεται μελέτη ώστε να επιτευχθεί η δυνατότητα σημασιακής διαλειτουργικότητας στα αποθέματα και συγκεκριμένα στο DSpace. Με τον τρόπο αυτό γίνεται δυνατή η συνδιαλλαγή και διαπραγμάτευση πληροφοριών μεταξύ συστημάτων, οι οποίες, ενώ μπορεί να είναι κατά βάση ετερογενείς, προερχόμενες από πολλαπλές πηγές και αδόμητες σημασιακά, μπορούν να συσχετίζονται και, βάσει συμπερασμών, να συνδυάζονται κατάλληλα με στόχο την ανακάλυψη νέας γνώσης. / The rapid growth of World Wide Web in the last years has led to an increase of the educational material that is available in digital way. As a result of this, searching and discovering of digital educational material is becoming more and more difficult. For this reason, digital education objects, or Learning Objects, have to be described using education metadata in order to facilitate searching, retrieval, classification and reuse of these objects. In the recent years, a lot of repositories have been built to store digital educational objects, like DSpace, EPrints and Fedora. Digital repositories make use of metadata to describe digital objects that are stored in their system. But we can note that although the main use of these repository systems is for educational purposes, we do not have the ability to enrich learning objects that are stored in these systems with educational metadata. Therefore, the main purpose of this thesis is to study the available educational metadata standards and to extend the available metadata sets of digital repositories in order to include and support metadata for education purposes. A main feature of most educational repositories is interoperability with other systems. Interoperability assures the cooperation of one repository with others by allowing the harvesting and using of digital objects stored in one place by other systems and services. For this reason, it is studied how educational metadata can be incorporated in a repository’s interoperability services, and mainly in the OAI-PMH service, which is supported by most repositories, but also in a new service named OAI-ORE. The implementation of these interoperability services is focused on the DSpace system. Finally, Semantic Web is the evolution of World Wide Web. In Semantic Web information is described by data, so this information gains meaning which gives the ability to machines to process this information which till now was meaningful only to humans. So, it is also studied how semantic interoperability can be achieved between repositories and specifically between repositories based on DSpace. This will give the ability to exchange information between systems. Although this information may come from different and heterogeneous sources, and although this information may be semantically unstructured, it can be associated and combined in order to discover new knowledge.