Design Considerations for an ELeGI Portal

ELeGI, the European Learning Grid Infrastructure, has the ambitious goal of fostering effective learning and knowledge construction through the dynamic provision of service-based contextualised and personalised learning environments. The success of this venture will depend to a considerable extent on the usability of such environments, and their usability in turn will depend on a successful strategy for the dynamic integration and maintenance of sets of services. The concept of the portal is therefore of considerable interest as it is often portrayed as a means whereby a user can access an integrated set of related information and services. This paper reviews the portal concept with a view to its suitability as a design basis for enabling technology that will address usability concerns. The paper proceeds by summarising the usability requirements of learning environments, reviewing some of the ideas currently associated with different types of portals (enterprise portals, institutional portals, usercentric portals, Grid portals), and concludes by deriving a taxonomy of portal characteristics against which the usability requirements of ELeGI can be assessed. USABILITY IN LEARNING ENVIRONMENTS A Learning Environment (LE) in ELeGI refers to the use of a dynamically integrated set of distributed services that are used directly by learners and teachers for educational purposes. Following the holistic approach taken to Quality of Service (QoS) in [1], Fig. 1 depicts usability requirements within a broader LE architecture. Teachers Users and Groups Management, Educational Resource Selection and Allocation, Activity Monitoring, Session scheduling Learners Interactivity, Groupwork, High quality simulations, Real-world input, SelfReflection Facilities, Privacy Content and Service Providers Developers Application and Service Interface Abstractions for Learning Environment actors Service Operators Manageability, Usage feedback, QoS Feedback Usability Features Interface Accessibility W3C Accessibility Guidelines Output formatted appropriately for interface device LE Middleware and QoS Sharing, Sessions, Security, Concurrency, Availability, Replication, Distribution, Coherence, Responsiveness, Timeliness, Interoperability, Resource Management, Resource Discovery and Location, Security, Identity Management Network Protocols, Operating Systems, Client-Server, Peer-to-Peer, Mobile Services, Authentication Authorities Low-level Infrastructure Physical Networks, Computers, and Interface Devices FIGURE 1: Usability Features within an EleGI Learning Environment Support Architecture Design Considerations for an EleGI Portal LeGE-WG 3 International Workshop: Towards a European Learning Grid Infrastructure 2 Firstly, major roles are identified with respect to a LE: institutions, teachers, learners, subject-specialists, service operators, content and service providers. Secondly, appropriate abstractions are determined by requirements analysis of each role, and groups of LE actors. Note that this approach also supports evolution of novel learning scenarios through continuous re-analysis of the principal roles and requirements, and as LEs evolve with changes in pedagogy and advances in technology. When this is done we can evaluate usability for learners from two viewpoints: i) the extent to which the LE middleware can dynamically realise usability features on top of a particular low-level infrastructure context; and ii) the extent to which the actual end-user access points can deliver these features. While the OGSA framework appears ideal for the research, development and deployment of LE middleware, it does not directly address user interface and usability issues per se. Therefore it must be complemented by a user interface management methodology and set of mechanisms, and this is exactly where the portal concept is of particular interest.