Abstract
E-learning has been a topic of increasing interest in recent years. It is often perceived as a group effort, where content authors, instructional designers, multimedia technicians, teachers, trainers, database administrators, and people from various other areas of expertise come together in order to serve a community of learners [1]. In a typical elearning scenario, many of the activities can be perceived and modeled as processes [16] and consequently be executed as workflows [19, 17]; there are even prototypical system developments that are experimenting with this approach [8, 11, 16]. On the other hand, there are increasingly many activities which aim at providing services of any kind on the Web [9]; these can occur as business-to-business or as business-to-consumer services and are generally subsumed under the term Web services. In this paper we suggest to combine the areas of e-learning and Web services, by providing electronic learning offerings as (individual or collections of) Web services as well. We elaborate on this by showing how content providers and content consumers (i.e., learners) can communicate appropriately through a Web service platform with its common description, publication, and retrieval functionalities. Finally, we indicate how a corresponding system can be realized. A common agreement seems to exist on the decomposition of a learning system from a functional perspective into a learning management system (LMS) that stores and manages content, an authoring system that helps creating content, and a run-time system that interacts with learners. We have shown in [16] how to perceive the central activities occurring in these components uniformly as processes or workflows which interact with resources (including people such as learners, administrators, trainers, and authors, and also including learning content), with one another (so that, for example, a learning workflow may trigger the execution of an authoring workflow or vice versa), and with the outside world (such as existing software systems) in predefined ways. In this paper we take these ideas one step further and show what the implications of this perception can be as soon as suitable languages are chosen for a description of the components and activities involved, and appropriate platforms are used for an implementation and enactment. In particular, we will show how to realize a logical organization as a collection of Web services, where learners can search for suitable content offerings and, if successful, configure an appropriate delivery, learners can additionally arrange for a suitable observation of their progress and achievements, and authors can adhere to content production services that can be called upon depending on the subject at hand. Generally, we try to design such learning services using tools and languages that are common in this area as far as possible. To this end, we will rely upon established Web service standards, since they appear sufficient for our purposes. In Section 2, we collect preliminaries relevant to our proposal from the e-learning field as well as from the area of Web services. In Section 3 we combine the two, and show how service providers and service consumers can be brought together in such a way that e-learning needs can be serviced via an appropriate platform. In Section 4 we discuss realization aspects which we are investigating in the context of our prototypical LearnServe system, and in Section 5 we offer some conclusions and directions for future study. This paper is an extended abstract of [18], where further explanations and details of the approach can be found.