Sharing Application Sessions for Peer-to-Peer Learning

Extract from article accepted in Workshop in Social Computing in Education in SocialComp09:

Educational institutions for all ages have been centered in the teacher: teachers providing materials, giving lectures, assisting students, marking exams and so on. Thus computer supported for learning has been built following such a model: supporting teacher activities with Course Management Systems (CMS) that provide students access to lecture materials, automate tests access, and assessment.
However, new educational paradigms are emerging; some of them bear similarity with new computer models such as the Peer-to-Peer (P2P) model. The P2P computer application model is built on the premise that system nodes are clients and servers at the same time. Likewise the P2P learning model claims that peers are students and teachers at the same time “learning from and with each other” [5].
P2P learning might be supported by computer systems in different ways. Since P2P learning is a distributed activity requiring no centralized support, in this work we are focused on exploring distributed systems support, specifically by P2P and Grid systems.
ULabGrid2 Framework for P2P Learning
Several of the previously discussed scenarios could be supported by different distributed technologies; however there was a scenario that was only provided by the ULabGrid framework [1], it provides the following functionality for several of the previous scenarios:
a) Sharing application sessions with an screen sharing system: the Virtual Network Computing system VNC [17] permits remote desktop sharing between several user. ULabGrid enables users to access different shared application session being executed on demand in a dynamic pool of Grid resources.
b) Sharing information with a shared data file sytem, in ULabGrid applications data was available to any of the applications sessions being executed in the pool of Grid resources.
To support other P2P learning scenarios we had extended the framework into a new version to be called ULabGrid2. The functionality that this new framework version incorporates is:
c) P2P direct communication, initially text-based messages.
d) Peers discovery by means of a network-based mechanisms.
The resulting ULabGrid2 framework is depicted in Figure 1.
Peer learners form a network connecting peers with each other. Peers are connected directly for communication or file sharing, and indirectly through a Grid resource for resource sharing and application session sharing. A social networking mechanism permits peers to discover each other through direct connections, who I communicate with, or through indirect connections, who I share an application session with.gridp2plearningframework

Figure 1. ULabGrid2 Framework

Use Case

To validate our framework and prototype we will perform a use case with a number of students. In this use case we will program a learning activity for students of a computer systems course. In this course students make use of a simulation package to investigate diverse system configurations. This learning activity is usually performed as a teacher oriented laboratory session. In contrast at the use case students will be provided with some initial data and instructions and the objectives of the learning activity, and they will have to perform the learning activity on their own and with the help of each other. The design of the use case is as follow:
1) Teachers give access to students to the UlabGrid2 system by providing them with a username and password; at the same time teachers form groups of 3 students to perform activities in small groups. Students enter the system and select the Moodle course that implements the prototype. All students will be assigned the same learning activity, although the system supports that each student group is assigned different activities. At that moment students can see who are in its group and which other groups are accessing the same course.
2) Students instantiate a remote application session in a Grid pool, only one session per group will be instantiated. Students access the session through the VNC client executed in their Web browser. Students perform the learning activity on his remote application session. Students of the small group will collaborate to perform the activity by sharing mouse control and communicating through a chat session. The application has a graphical user interface that permits user to perform the activity by dragging icons, double clicking in icons and entering small texts. Figure 3 shows the interface seen by an student performing this activity.
3) At any time students can be interested in accessing others students current work. In order that one student can see others’ sessions, he must have shared his session with others. A student might access others current sessions to check how much they have accomplished and to obtain ideas on how to proceed. Students can enter the chat room corresponding to that session to ask questions to the group members about the current application session, as shown in Figure 3.
4) When the learning activity is completed, each group has to publish his results in a shared repository. Then other students can access the results of other groups to compare them with their results.

Figure 3. ULabGrid2 User Sharing Session interface