Hypermedia-based discovery for source selection using low-cost linked data interfaces

Evaluating federated Linked Data queries requires consulting multiple sources on the Web. Before a client can execute queries, it must discover data sources, and determine which ones are relevant. Federated query execution research focuses on the actual execution, while data source discovery is often marginally discussed-even though it has a strong impact on selecting sources that contribute to the query results. Therefore, the authors introduce a discovery approach for Linked Data interfaces based on hypermedia links and controls, and apply it to federated query execution with Triple Pattern Fragments. In addition, the authors identify quantitative metrics to evaluate this discovery approach. This article describes generic evaluation measures and results for their concrete approach. With low-cost data summaries as seed, interfaces to eight large real-world datasets can discover each other within 7 minutes. Hypermedia-based client-side querying shows a promising gain of up to 50% in execution time, but demands algorithms that visit a higher number of interfaces to improve result completeness

A model for hypermedia learning environments based on electronic books

Designers of hypermedia learning environments could take advantage of a theoretical scheme which takes into account various kinds of learning activities and solves some of the problems associated with them. In this paper, we present a model which inherits a number of characteristics from hypermedia and electronic books. It can provide designers with the tools for creating hypermedia learning systems, by allowing the elements and functions involved in the definition of a specific application to be formally represented A practical example, CESAR, a hypermedia learning environment for hearing‐impaired children, is presented, and some conclusions derived from the use of the model are also shown

Hypermedia for language learning: The FREE model at Coventry University

Coventry University is pioneering the integration of hypermedia into the curriculum for the teaching of Italian language and society with the creation of a package based on Nerino Rossi's novel La neve nel bicchiere. The novel was already in use as a basic course text, and developing a hypermedia package was felt to be the ideal way of creating a more stimulating means of access to it. The procedure used in creating the package is described, as are its contents, the ways in which the students use it and the tasks they are given to perform, the feedback from the students, and its impact on their performance. The testing of the prototype has helped in creating a new cognitive model: the FREE (Fluid Role‐Exchange Environment) which functions as a fluid and interactive ‘pool’ where the three main actors, or act ants, ie. the learner, the lecturer and the computer, exchange roles. Within the FREE, students were involved in the construction and evaluation of the courseware, as well as testing the various versions of the prototype. The development and use of hypermedia inside and outside the classroom has made it possible to change both the students’ and the lecturer's attitude towards the material being learnt. However, the courseware does not seem to equip students sufficiently for essay writing, and this problem needs further investigation

Reviews

Brian Clegg, Mining The Internet — Information Gathering and Research on the Net, Kogan Page: London, 1999. ISBN: 0–7494–3025–7. Paperback, 147 pages, £9.99

Teaching new media composition studies in a lifelong learning context

Governmental proposals for lifelong learning, and the role of Information and Learning Technologies/Information Communication Technologies (ILT/ICT) in this, idealistically proclaim that ILT/ICT empowers learners. A number of important governmental funding initiatives have recently been extended to the development of ILT in further education, which provides a particularly appropriate environment for lifelong learning. Yet little emphasis is given to more problematic research findings that students may be ‘disarmed’ in the process of learning to use technology. In the current global shift towards new forms of multimedia literacy, it is important to recognize human diversity by carrying out research focusing on the actual problems students face in adapting to Web‐based technology as a new authoring medium. A case study into multimedia creative composition carried out with FE students in 1996–9 found that students tend to experience a problematic but potentially useful period of ‘creative mess’ when authoring in multimedia, and that ‘scaffolding’ strategies can be useful in overcoming this. Such strategies can empower students to derive benefits from multimedia composition if close attention is given to the setting up of the learning environment: a teachers’ model for supporting novice hypermedia authors in further education is proposed, to assist teachers to understand and support the learning processes students may undergo in dynamic composition using new media technology

Reviews

Teaching and Learning Materials and the Internet by Ian Forsyth, London: Kogan Page, 1996. ISBN: 0–7494‐ 20596. 181 pages, paperback. £18.99

Unifying Distributed Processing and Open Hypertext through a Heterogeneous Communication Model

A successful distributed open hypermedia system can be characterised by a scaleable architecture which is inherently distributed. While the architects of distributed hypermedia systems have addressed the issues of providing and retrieving distributed resources, they have often neglected to design systems with the inherent capability to exploit the distributed processing of this information. The research presented in this paper describes the construction and use of an open hypermedia system concerned equally with both of these facets

User-centred design of flexible hypermedia for a mobile guide: Reflections on the hyperaudio experience

A user-centred design approach involves end-users from the very beginning. Considering users at the early stages compels designers to think in terms of utility and usability and helps develop the system on what is actually needed. This paper discusses the case of HyperAudio, a context-sensitive adaptive and mobile guide to museums developed in the late 90s. User requirements were collected via a survey to understand visitors’ profiles and visit styles in Natural Science museums. The knowledge acquired supported the specification of system requirements, helping defining user model, data structure and adaptive behaviour of the system. User requirements guided the design decisions on what could be implemented by using simple adaptable triggers and what instead needed more sophisticated adaptive techniques, a fundamental choice when all the computation must be done on a PDA. Graphical and interactive environments for developing and testing complex adaptive systems are discussed as a further step towards an iterative design that considers the user interaction a central point. The paper discusses how such an environment allows designers and developers to experiment with different system’s behaviours and to widely test it under realistic conditions by simulation of the actual context evolving over time. The understanding gained in HyperAudio is then considered in the perspective of the developments that followed that first experience: our findings seem still valid despite the passed time

Evaluation in a project life‐cycle: The hypermedia CAMILLE project

In the CAL literature, the issue of integrating evaluation into the life‐cycle of a project has often been recommended but less frequently reported, at least for large‐scale hypermedia environments. Indeed, CAL developers face a difficult problem because effective evaluation needs to satisfy the potentially conflicting demands of a variety of audiences (teachers, administrators, the research community, sponsors, etc.). This paper first examines some of the various forms of evaluation adopted by different kinds of audiences. It then reports on evaluations, formative as well as summative, set up by the European CAMILLE project teams in four countries during a large‐scale courseware development project. It stresses the advantages, despite drawbacks and pitfalls, for CAL developers to systematically undertake evaluation. Lastly, it points out some general outcomes concerning learning issues of interest to teachers, trainers and educational advisers. These include topics such as the impact of multimedia, of learner variability and learner autonomy on the effectiveness of learning with respect to language skills

A spiral model for adding automatic, adaptive authoring to adaptive hypermedia

At present a large amount of research exists into the design and implementation of adaptive systems. However, not many target the complex task of authoring in such systems, or their evaluation. In order to tackle these problems, we have looked into the causes of the complexity. Manual annotation has proven to be a bottleneck for authoring of adaptive hypermedia. One such solution is the reuse of automatically generated metadata. In our previous work we have proposed the integration of the generic Adaptive Hypermedia authoring environment, MOT ( My Online Teacher), and a semantic desktop environment, indexed by Beagle++. A prototype, Sesame2MOT Enricher v1, was built based upon this integration approach and evaluated. After the initial evaluations, a web-based prototype was built (web-based Sesame2MOT Enricher v2 application) and integrated in MOT v2, conforming with the findings of the first set of evaluations. This new prototype underwent another evaluation. This paper thus does a synthesis of the approach in general, the initial prototype, with its first evaluations, the improved prototype and the first results from the most recent evaluation round, following the next implementation cycle of the spiral model [Boehm, 88]