Overall Portal Framework as in “Web-Based Computing”/”Virtual University” A portal is a customizable web-based (WebWindows) approach to a given application area. For computing, the portal architecture will need to support seamless access to distributed national resources. These resources include distributed databases, prototypical and large scale scientific simulations, immersive visualization environments, as well as colleagues, mentors, and experts in the field. For education the resources are courses, quizzes, homeworks etc. For all portals, the resources will be accessed in asynchronous and synchronous modes including real-time interactive capabilities. A base architecture for such portals is defined by emerging web-based, distributed object, component technologies and information repositories standards. Architecture of a Collaborative Portal It is unrealistic today for any one effort to build a complete online education or computing environment. Rather one must integrate a system from a variety of different sources, which could include education providers like Blackboard and WebCT. It will be critical to make good use of systems and technologies designed for the much larger Web browsing and e-commerce arenas. Several powerful technologies (such as CORBA and Jini) and more importantly systems (such as E-Speak and iPlanet) are emerging as candidate frameworks to integrate distributed information systems. We intend to evaluate these new approaches starting with the impressive Ninja system from UCB, which is for instance aimed at supporting mobile hand-held clients. We think these new systems are consistent with our methodology built around CORBA but the new frameworks are very powerful and can be used to implement many capabilities built by hand in systems like TangoInteractive. We suggest building education/computing specific portals as a set of special services on top of this framework. These must support the special collaborative needs of each application and special services such as for education: assessment, performance (grading) support, annotation. There are also distinctive “educational objects” – quizzes, homework, glossaries as well as the curriculum pages with appropriate hierarchical structure. For computing of course, services include visualization and special objects include program tasks. These will need special XML support and here we will adopt local standards as necessary and evolve these as international community efforts (such as Grid Forum, Computing Portals Forum and in education IMS and the IEEE Learning Technology Standards Committee) mature. Requirements such as supporting different authoring models or different visualization systems are hard, as it requires unification of services such as those for customization, collaboration and events. This will be a key research area as such unified services are essential for the basic strategy of allowing components from multiple academic and commercial sources. A simpler version of this challenge (being addressed by Grid Forum) is well-defined XML interfaces to allow interoperability of data streams. Customization and Portal Specification We expect commercial portal technology to support user customization of the portal environment. This includes two types of capabilities of which the second can be used for assessment in education portals. Firstly we have the capability, probably XML based, to pick and use the components shown on a particular web-page. We have designed a simple “portalML” to describe layout and source of page components and further their collaborative structure. We expect this to be a reasonable start but that several commercial choices developed for the broad portal market will emerge and we will customize these for use in education. Assessment in Education Portals More interesting than this overall way of specifying dynamic pages, is the methodology for tracking user interactions with the user environment. As discussed in the Syracuse theses of Lee and Sen, this can be done server side when it reduces to the classic analysis of Web Server access logs. More interesting is the tracking of client side events where the challenge is basically datamining user relevant information. We will on one hand build in support for this as part of our event service and research extensions of the simple analyses in the two theses to automatically derive user profile and learning assessment information. This client side event information can be used to support universal access as described by Fox and Gilman from the Wisconsin Trace center. Collaboration Service A web-based computing/virtual university/training approach implies that collaboration is a service that shares web-based distributed objects. Previous systems have tended to support either synchronous or asynchronous collaboration modes but based on our current experience, we suggest that all modes of collaboration can and should be unified. Initial synchronous deliveries have has some success using systems like Microsoft NetMeeting, NCSA’s Habanero and TangoInteractive. However combining broader needs with the new technologies available, suggests that it is best not to evolve the older systems but rather build collaboration on top of the event service of a base (Ninja or equivalent) framework. We will allow this to support either synchronous delivery or event archiving and later delivery of a session. Session control will be implemented in XML using the generalized portalML described above. We have found that developing shared animations (for education) is quite difficult in current systems like TangoInteractive, which only easily support complex collaboration-aware applications. One needs to improve VNC or equivalent technology to allow both shared display and collaboration-unaware applications, which are less flexible but much easier to author. Events for audio video conferencing One continual area of difficulty is the variable quality in digital audio video conferencing and here higher speed networking and quality of service will address some of the difficulties. We will track the ANL/NCSA Access Grid project at the high end but for many educational uses commercial systems like RealAudio/Video can be used. We think one can build an interesting new approach using Current approaches involve 3 distinct buffer (aka event) sizes 1) Real-time audio/video conferencing (CUseeMe, Tango, Access Grid) fraction of a second 2) Real Audio (several seconds) 3) Download file locally and play (indefinitely large) Thinking of AV as events (with very fast real time processing if necessary) of a small size which can be concatenated for modes 2) and 3) (and transmitted redundantly for mode 1) appears to allow more flexible robust A/V conferencing where you can dynamically move between 1) 2) or 3) dependent on line-quality and lateness of arrival of listener to a session. This is perhaps a special case of integration of the synchronous and asynchronous collaboration enabled by the event based approach described above. It also emphasizes that a difficult issue is retaining real-time (high) performance for synchronous modes even with intermediate buffers and filters (for user customization such as that needed for universal access). A simple but important issue is "event format" (e.g. XML DTD for events) which allows very fast retrieval of critical tags and allows a more relaxed analysis to fully process (in a message lingo, we need certain tags in message header). The event model is the most natural ("best") for all portals. We believe a lot of current “robustness” difficulties with current audio-video conferencing, can be handled in this new approach, as A/V streams are “just” events and we need “just” to build robust distributed (event) databases – a difficult but solved problem.