1. Introduction - Universidade de Lisboa

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Computer workstations with multimedia and network capabilities and is intended to be used in small or ... DDE Client+TCP-IP Client/Server. Virtual Work Room.
CYTED-RITOS International Workshop on Groupware, Lisbon, Portugal, September 1995

Design and Implementation of a Virtual Learning Environment Joaquim Sousa Pinto, Joaquim Arnaldo Martins Universidade de Aveiro / INESC Campus Universitário, 3800 Aveiro Phone: +351 34 370500 Fax: + 351 34 370545 Email:{jsp, jam}@inesca.pt Abstract: The nature of computer based learning and instructional environments that support it have changed dramatically in the last decade. The growth of hypertext, hypermedia and multimedia provided the capabilities necessary for developing complex learning environments. The system described in this paper is being developed to be used in Personal Computer workstations with multimedia and network capabilities and is intended to be used in small or medium learning scenarios. The tools developed span several topics, from navigation trough desktop reality, hypermedia tools for editing and playing learning material and cooperative asynchronous and synchronous tools.

1. Introduction Computer-based learning has a relatively short biography, emerging from programmed instruction in the lately 60’s. In the later 80’s, the growth of hypertext, hypermedia and multimedia provided the capabilities necessary for developing complex learning environments. Learners are seduced by these environments because their intellectual involvement in the learning process is essential. They are no longer passive recipients of information; they are actively involved in the knowledge construction [Jonassen93]. The computer computational functionality is being used to support these processes rather than to present information. Currently hypermedia and multimedia are the chosen platforms for implementing these environments, largely because of their open architecture. Hypermedia learning material can be developed in less time, is more flexible for modifications than traditional learning material and can be distributed relatively fast over computer networks in comparison with the traditional way of sending learning material over ordinary mail. Information technology opened the way towards interactive and computer based multimedia learning material. Specially the customisability of courseware may eliminate the drawback of the inertia of traditional learning material [Alexander92]. However, communication technology offers more than only a vehicle for fast distribution of multimedia and courseware. The next, or third, generation of distance learning environments will put more emphasis on exploiting communication technology as a tool for groups to cooperate within learning processes. This system is a research and development project in INESC/University of Aveiro. This virtual environment follows the conceptual model of a traditional university, the University of Aveiro, and should adhere to a users mental model of navigating through the different departments, each one dedicated to one or more subjects and the different rooms in each department dedicated to different activities: the lobby for user identification, the boards on the lobby for help and news announcement, the post mail room for mailing activities, the ordinary class rooms dedicated to synchronous and asynchronous classes and the library room to store

and to retrieve the courseware. The main goal of this project is to provide a third generation distance learning environment in which participants (teachers and students) can engage in learning and training programs without the lack of changing their mental models, in a first step. This environment will provide courseware in hypermedia documents stored in a multimedia database located in a virtual library. Such courseware can be used in work rooms by a teacher to give a magistral class or by groups of students for group study. The students are also able to play the courseware for self study purposes, send mail to each other or to teachers and to create discussion groups. The courseware used on our tools can be loaded, prepared and annotated by means of a hypermedia document editor. In the next sections we will describe the metaphors used in the design of such system as well some of the decisions taken in the implementation. Some of these tools are already implemented while others are still in development.

2. System Architecture This system was designed to be used as an asynchronous/synchronous set of tools to aid the students in the study task. Conceptually the system follows a traditional University model. The users can navigate freely trough the Campus, which means using the navigation tool implemented in the system. After choosing the desired department, at the lobby, the users are invited to self identify to have access to work rooms gallery, or to register at the registration desk. The registration is important to evaluate what functionality’s are available to such user in that department. At the department lobby, a public board with news and announcements, a help board and the entry point to the work rooms gallery are also available. The work rooms gallery access is user identification dependent. On a work room a user has table with a set of tools. These are tools for conferencing control, to individual work or for cooperative activities. The system architecture is presented in the Figure 1. VIRTUAL LEARNING ENVIRONMENT Workstation 1

Workstation n

Virtual Work Room Synchronous Conference Tools

Virtual Work Room

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Figure 1 - System architecture

The Virtual Work Room has Asynchronous Conference and Synchronous Conference tools to allow cooperative activities among groups of users; the Hypermedia Document Editor to prepare and annotate the courseware to be used with the cooperative tools; and the Agenda, used as scheduler and temporal support for conferences. The Virtual Library is used to store the asynchronous conferences messages, the courseware, the agenda data and the system database. Before we discuss in detail each tool present in the virtual work rooms, we will describe the Navigation System, that allows to travelling along the virtual campus..

3. The Navigation system Our campus is composed a several independent buildings, each one dedicated to a specific matter (Ceramics, Biology, Electronics, Mechanics, ...). To provide a navigation system, desktop reality based, we filmed a set of sequences in our campus and composed them as presented in the Figure 2. We have two different type of films. Films with circular sequences and films with linear sequences of frames. Connection ...-C

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Connection C-B Point C

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Figure 2 - The Navigation System Model

The linear sequences, for example from A to B path, simulates the user movements. Note that to simulate the movement back, from B to A path, we need to have another sequence; normally we don’t walk back. The circular films allow the users to move around near of the entry points, as for example on the buildings entrance (tagged as Point A in Figure 2), in the department lobby (Point B) and at work rooms' gallery (Point C). In these sequences, the frames allowing access to another place may be indicated to facilitate the user perception. To control the film, we need to control the frame sequence as well to provide entry points in several frames that allow the users to jump into another scenes. To control the frame sequence, we developed in Visual Basic an application that controls trough MCI (Multimedia Control Interface) [Microsoft91] commands the frame sequence. We divided vertically the display in two half sizes. If the user clicks with the mouse on the left half side, the operation performed is new_frame = old_frame-1. If the user clicks on the other side, the task performed is new_frame = old_frame+1. As referred before, those movie films (with n frames) were done in a circular sequence. This means that frame_n+1 = frame_1 if a user is turning to the right and frame_1-1 = frame_n if the user is turning to the left. At this point we needed to decide about a certain number of parameters - video format, frame sizes and number of colours, the step between two consecutive frames in the circular frame sequences. We used the Video for Windows format to digitise the films with a frame size of 320x240 pixels with 16 colours. Due to the video size and storing format, we needed to decide about the number of frames in circular sequences: 8 frames that means a step of 45o between frames, 12 frames → 30 o, 16 frames → 22,5 o, 24 frames → 15 o, 36 frames → 10 o, 72 frames → 5 o. We have done some tests and we concluded that the number of frames/circle depends on the number of entry points in such circular sequence. In a sequence with up to four entries, we can 









use a 24 frames circle (15 o between frames). In scenes overcrowded of entry points is necessary to use a 36 frames sequence. With more than 36 frames/sequence the system becomes overloaded due the film size (that is stored in the Virtual Library).

Figure 3 - Electronics Department entry

Figure 4 - Identification desk

To place anchors over the film on circular sequences, we developed an editor that allows the users to define on each frame sensitive zones (rectangles) as well to name those sensitive zones. We can have several sensitive zones or entry points in one frame. When the mouse crosses one sensitive zone, the mouse shape changes from the normal arrow to a hand, as shown in figures above, and the “Action” text box changes to the name of such sensitive zone. In the near future, we plan to migrate our films to the MPEG format, due the compression mechanisms that allow for the same file length a bigger frame number (or less step between two consecutive frames). The migration work is minor since we have now available MPEG app’s controlled by MCI.

4. The Virtual Room After a user Navigate trough the Virtual Campus and to decided what department to visit, he is now able to access the Virtual Work Room’s. The Virtual Work Room is composed by several tools, designed for stand alone and cooperative activities. The accessibility to these tools, as well as the functionality of each one, is imposed by the user identification, as described in the previous section. In the next sections we will describe the Virtual Work Room tools.

4.1 Agenda The agenda is a tool designed to support the conferencing system. It allows users to schedule conferences, synchronous or asynchronous. In the asynchronous conferences the users should indicate the starting and finishing time, the users allowed to participate in the conference and the document name that will be discussed into the conference. The system warns the user each time he enters in the system about the conferences running and the conferences near to begin. In synchronous conferences, the users should schedule the conference date, the time duration and the documents to be used in the conference. Since each user may have a copy of the documents before the synchronous conference start, the agenda is responsible to upload the documents in the users briefcase before the beginning of a conference. At the time defined to start the conference, the agenda should start the session.

4.2 Synchronous Conference Tools The Synchronous Conferencing is performed by a Cooperative Player application. From the top view, such Cooperative Player consists of a Hypermedia Public Window controlled by a Global Pointer that can be handled by a Conference User. It was developed to work with the TCP/IP protocols. The network communications are all done through sockets over UDP multicast packets. With this procedure, the data sent by a user to the network is received by the other conference members. For further details in the Cooperative Player implementation, see Pinto94B. 4.2.1 The Synchronous Network Configuration In centralised training and tele-teaching systems there is a conference server that deals with the social rules and with the database needs [Derycke93, Kaye92, Santos92]. In such a system, the participants in the conference should know, in advance, what is the server location; people do not have access to other libraries nor can meet at different places. For big conferences this scenario fits well, but for small conferences where it is needed some flexibility, it should be possible for the various participants to decide about the best ‘room’ to have the meeting and to have access to all documents of each participant. Each site must be able to host at any time a conference and so it must support a series of tools to help in the organisation, preparation and execution of the meetings. Such a distributed system as some advantages, namely: the independence of a specific machine or network connection (it is possible to choose another host site) and the possibility of having several conferences running simultaneously over the same network, providing that groups are independent. The disadvantage is that the client must be prepared to play also the server role (when it is chosen as a host) and must deal with the problem of replicated objects that belong to a group of people in an efficient way [Abdel88]. We used the ‘Conference Proponent’ keyword to designate the host that starts a conference and plays the server role. Since we can have several conferences running simultaneously, the conference proponent’s exchange messages trough the Global Channel, as shown in Figure 5. All other conference specific messages, are multicasted trough the Conference Channel, one per conference, to guarantee the messaging independence among conferences. Synchronous Cooperative Player Conference Tools Public Screen

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Figure 5 - Synchronous Conference Model

To support the communications over the Global Channel, the Conference Proponent, is responsible for maintaining the following data related with its own conference: a Users List, list with the names and the privileges of each user in the conference. The Users List grows or shrinks with the entry/exit of users; a Global Pointer Queue, queue containing Global Pointer user requests; 



To be WYSIWIS consistent, all users should see the same thing at the same time. The conference proponent may store information about the 'distributed overhead projector' the window size and current scroll bar positions; The tasks associated with the Conference Proponent are: ❍ to create and finish conferences; ❍ disseminate, when requested, conference information (trough the Global Channel); ❍ accept or refuse new users in the conference. ❍ to put a user out of the conference, remove or change the user’s position in the Global Pointer Queue; ❍ evaluate and disseminate the result of global voting processes; ❍ after the acceptance of a new user in the conference, to provide him all information related with the conference - users list and global pointer queue - and evaluate the new user window size. If the new user window size is less than the public window, then the conference proponent may resize the public window to a new value which will be the maximum value possible on the workstation with less graphical capabilities. In this conference model, another important role is the Global Pointer Owner. The tasks associated with such role are: ❍ to control the public window, which implies that all actions performed by him (mouse and scroll bar movements) will be reflected in all other conference stations. Some menu commands, like Open Lesson, will be sent also to other conference members. Besides the public window is being controlled by a remote station, all stations remains with self control. This means that the Windows cursor remains locally controlled. To show the Global Pointer movements performed by the Global Pointer Owner, a dummy pointer is drawn. This implies that all stations, except the Global Pointer Owner, can see two pointers over the Public Window. Another tool implemented to support the Synchronous Conference Model is a Voting Mechanism, This tool, besides being used by the conference proponent to ask the other users about new conference users, can be can be used also when a voting process is needed to make decisions. To allow message exchanging among the users in the conference, a Message Exchange tool was implemented. This tool allows the message exchanging from one user to another, from one user to a group of users. In case of a malfunctioning of the conference proponent workstation, and since all users have the conference information, the conference does not breakdown. Another user can take this place and play the server role. 

4.2.2 The Synchronous Conference Modes The Synchronous Cooperative Session adheres to the mental model of a typical classroom. The objective of a Synchronous Cooperative Session is to play and annotate pre-prepared courseware. We have three kinds of social roles: teachers or tutors, students or learners and audience each one with rights and duties. To support such social roles, we developed two conference models: the Magistral Class and the Group Study, combined with two access types, Public and Private. In Public sessions, all users are accepted unconditionally in the conference, while in Private sessions, the conference proponent has the privilege to admit or to refuse unconditionally the new user, to change the required social role, or to put the problem to the other participants through a voting process. The Magistral Class mode adheres to the mental idea of a typical classroom. We have teachers or tutors that are users with some special rights, the students that can interfere within the conference development and the audience, that can only assist but not interfere in the class. Users have the possibility of playing and made annotations over pre-prepared documents. In order to store private annotations over the courseware, each user must have a copy of the

document. Normally in this model the teacher is the conference proponent. In an Assisted Class or Group Study, the teacher or tutor and audience roles do not exist, which means that if a teacher is present he or she does not have special privileges. We are in a democratic session and all users have the same rights and duties.

Figure 6 - Synchronous Cooperative Player

We are looking for the introduction of voice servers [Azevedo94] which is of topmost importance in a conference, as well studying the introduction of video.

4.3 The Asynchronous Tools The asynchronous tools are designed to support the students study process. We developed three tools to support such kind of study: the Asynchronous Conference, the Proposals and Hypermedia Mail. Asynchronous Conference Tools Asynchronous Conferences

Hypermedia Mail

Agenda

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Figure 7 - The asynchronous conference tools

Each Asynchronous Conference is a group of users engaged during a certain period of time in the production or discussion over a set of documents. Since the work is asynchronous, the cooperation among the users is done trough the virtual library. The virtual library is responsible for storing the conference related documents as well for assuring that a user does not destroy or damage the work produced by another user. To guarantee the non interference, each time a user requests a file from virtual library with write privileges, is flagged as “in use”. Only this user is allowed to store again the file in the library with the same name. If another user requests the same file with the same rights, this user is not allowed to upload the file with the same name. This allows later users to discuss and even integrate the work. This method of interference control is based on the optimistic concurrence control developed by Akscyn on the KMS system [Akscyn88]. Each time a user logs into a conference, the system warns the user about the document name locked by him. To avoid that a document remains indefinitely flagged as "busy", the

system allows users to define at the conference creation time the maximum time allowed for a user to lock a document. When a document lock expires, the document is able again to be retrieved with write rights. The Proposals tool was designed to support user's proposals associated with a voting. A user makes a proposal and then opens a voting process. During a certain period the users are able to vote. Such period is controlled by the Agenda tool. We developed three voting modes, called public or raised hand, anonymous and secret. In the first mode, you can know the results before the end date of the votation and you can know also the other users choice. In the second case, you can know each time the results of the votation, but you are unable to know who voted in whom. In the third method, you only can know the results after the end date of the votation. Since the votation is secret, a user is unable to know the other users choice.

Figure 8 - Asynchronous Proposal (Vote a Proposal, Results from a Public Votation)

The Hypermedia Mail system is analogous to a mail provided with the UNIX systems: an in box, an out box and a temporary box to store mail in preparation. Some of the differences are: ❍ is possible to a user to send a mail with references to hypermedia documents. When a user selects in a mail a reference to a document, the document is retrieved from the virtual library and opened with the Hypermedia Document Editor; ❍ the system is able to deal with pre-dated messages, that means a user can send a mail now but the system only delivers such message in the date indicated on the mail.

4.4 Hypermedia Document Editor As described before the environment is based on the use and manipulation of hypermedia material. Our hypermedia tools [Martins94, Pinto94A] were developed under the metaphor of an electronic overhead projector. Each tool is an electronic overhead projector on which hypermedia documents composed of piles of electronic transparencies, can be displayed either in a simple sequential order or in a more sophisticated so called web structure [Nielsen90]. 4.4.1 Hypermedia Document Structure In our approach, one hypermedia node consists of a transparency which may, or may not, be covered by one or more overlaying layers. One hypermedia document consists of a set of transparencies, as shown in Figure 9. A transparency can be filled with multimedia objects and subsequently connected by anchors to other transparencies, layers or hypermedia documents. A transparency yields anchors and multimedia objects while a layer only hold multimedia objects. A multimedia object is any piece of information such as sound, graphics, text or video. An anchor connects a transparency with another transparency, a layer or a hypermedia document. For a further and detailed discussion see [Pinto95].

}

Layers

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Figure 9 - The Hypermedia Document Structure

4.4.2 The Hypermedia Engine Our hypermedia structure [Martins93, Pauwels93, Pinto94A] is controlled by anchors, that as described by Nielsen, are the source point of the links. As referred, our ‘electronic overhead projector’ has the possibility of establish links between transparencies, layers and other lessons. The result of an anchor activation is to follow the link until the destination, that depending on the anchor type can be another transparency, a superimposed layer, an alternated layer or even another lesson. Anchors to transparencies: This kind of anchor allows the user to “jump” into another transparency. When activated, the transparency over the ‘distributed overhead projector’ (dop) is removed with their associated layers and the destination transparency is displayed. Anchors to layers: The capability of inserting layers over a transparency is a powerful feature. This allows the user to combine information in several ways, depending on the anchor activation order. The Hypermedia Document Editor provides two different mechanisms of layer handling: superimposed layers and alternated layers, that will be discussed in the next sections. Anchors to superimposed layers: An anchor to a superimposed layer allows the user to superimpose the destination layer over the currently displayed transparency and layers, if any. An important feature of the anchors to layers is the fact that they have an on/off behavior. Anchors to alternated layers: An anchor to an alternated layer means that, from a set of layers, a user can have only one layer displayed at a time over the transparency. If there are one or more layers displayed and the user selects an anchor to an alternated layer, the Hypermedia Document Editor removes all overlayed layers from the ‘dop’ and displays the anchored layer. Anchors to lessons: Anchors to lessons complete our set of anchors. They can be helpful to combine lessons in order to generate new lessons. When the user selects an anchor of this type, the Hypermedia Document Editor closes the current lesson and opens the anchored lesson. As a Windows application, the Hypermedia Document Editor is a menu based application with the most used commands associated with shortcuts and placed in a toolbar. To allow the user to know the current point in the hypermedia structure, a status bar is also displayed indicating the current transparency and topmost layer. To have a general idea of the “look and feel” of the user interface, see Figure 10. The Hypermedia Document Editor deals with two classes of OLE entities: Multimedia Objects and Anchors. Such object classes are organised and displayed in a window-based structure [Microsoft92]. Each element is placed in an independent window that is able to respond to the mouse input.







Figure 10 - Hypermedia Document Editor

4.5 Virtual Library The Virtual Library stores the courseware used in the conferences, the Agenda and system databases, the messages and protocols used in the asynchronous tools and the videos and sounds used in the Navigation System. The Virtual Library can be visited trough the Navigation tool, or browsed trough the Virtual Work Room facilities. As a first approach we decide to store and distribute the courseware in MS-DOS files. Nevertheless, to have organised libraries of multimedia courseware (text, sound, image, video) and to manipulate and access them in an efficient way it is needed a distributed multimedia database or a high level API able to handle different types of databases and/or file systems, as shown in Figure 11. Hypermedia Tools

Data Manager DDE Client

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Multimedia Information Mediator Figure 11 - Virtual Library Model

Hypermedia documents may have an enormous amount of data. That puts several problems,

such as large databases and long transmission times. The migration of the objects should be minimised and compression mechanisms taken into account. It is also important to look for distributed storage systems, since the documents may be spread over several rooms and libraries. A future development in this area will be the integration of such databases in the WWW environment [Lee94], allowing a simple a simplest and open management way and integrating the HTTP Protocol [Lee93] for data transferring.

5. Conclusion This paper described a conferencing architecture, able to support simultaneously several conferences, having as one of the major strengths a non static purpose of the workstations. Any station can be a conference server or a conference client and the system does not requires a server dedicated to the inter-conferencing control. We described a navigation system desktop reality like using real video frames to move the users among the services offered by the system and a set of hypermedia tools based on a new hypermedia document structure with powerful combination of transparencies and layers that uses the overhead projector and distributed overhead projector as metaphors.

6. References Abdel88

Akscyn88

Alexander92

Azevedo94

Lee93 Lee94

Derycke93

Jonassen93

Kaye92

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Science, Vol 90, Springer-Verlag, Berlin Heidelberg 1992. Joaquim Arnaldo Martins, Joaquim Sousa Pinto, “Hypermedia Courseware Tools for MS-Windows Environment”, In Proc. (AACE) ED-MEDIA 94, World Conference on Educational Multimedia and Hypermedia, Vancouver, Canada, 1994, June 25-29, pp 379-384. Microsoft Corporation, “Microsoft Windows Multimedia - Programmer’s Reference”, Microsoft Press, 1991 Microsoft Corporation, “Object Linking and Embedding - Programmer’s Reference”, Microsoft Press, 1992 Jacob Nielsen, “Hypertext and Hypermedia”, Academic Press, 1990 Hubert W.J. Borst Pauwels, Joaquim Sousa Pinto, Beatriz Sousa Santos, Joaquim Arnaldo Martins, “An Integrated Courseware Editor Based on OLE Technology” In: Human Computer Interaction, Vienna Conference, VCHCI’ 93. Grechenig T., Tschelig M.,(Eds.), Lectures Notes In Computer Science, Vol 733, Springer-Verlag, Berlin Heidelberg 1993, pp. 439-440. Hubert W.J. Borst Pauwels, Joaquim Sousa Pinto, Beatriz Sousa Santos, Joaquim Arnaldo Martins, “Integrating Existing Applications in Hypermedia Learning Material (General Issues & Experiences with OLE technology)”, In Proc. ED-MEDIA 94, World Conference on Educational Multimedia and Hypermedia, Vancouver, Canada, 1994, June 25-29, pp 444-449. Joaquim Sousa Pinto, Hubert W.J. Borst Pauwels, Joaquim Arnaldo Martins, Beatriz Sousa Santos, “HyDE: a hypermedia document editor based on OLE technology”, In Proc. of 1994 International Conference on Multimedia Computing and Systems, Boston, USA, 1994, May 14-19, pp.375-381. Joaquim Sousa Pinto, Joaquim Arnaldo Martins, “CHEaP: A Cooperative Hypermedia Editor and Player”, In Proc. of (SBT/IEEE) ITS’94, Rio de Janeiro, Brazil, August 22-26, pp. 512-516. Joaquim Sousa Pinto, Joaquim Arnaldo Martins, Hubert W.J. Borst Pauwels, Beatriz Sousa Santos, “Hypermedia Authoring Tools based on OLE technology”, to appear in Multimedia Tools and Applications - An International Journal, Kluwer Academic Publishers, 1995. Adelino Santos, “CoMEdiA: Conceptualization and Realization of Cooperative hyperMedia Editing Architecture” in Experiences, Hyperstructure Concepts, and Cooperative Work, Proceedings of the 2nd Workshop on Multimedia, Darmstadt, 4-5 May, 1992, pp. 170-186.