DEVELOPING WEB-BASED VIRTUAL CLASSROOM BASED ON IMS LEARNING DESIGN SPECIFICATION Feng-Hsu Wang Department of Computer Science and Information Engineering 5 Teh-Ming Rd. Gwei Shan District Taoyuan Country Taiwan 333
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experience [2][3][4] as well as fostering the sense of community [5]. However, existing web-based virtual classrooms reveal the following common problems: (1). the absence of a well-designed standard for sharing and integrating the activities and resources in a virtual classroom incurs the high economical cost of developing a web-based virtual classroom. (2). A web-based virtual classroom is often designed and implemented by engineers from non-educational experts. As a result, the established learning virtual classroom is not flexible enough to meet the needs of instructors.
ABSTRACT In this paper, an instructional model that describes the organization and processes of virtual classroom is proposed. Using this model, a teacher can describe the specification of a virtual classroom according to his/her instructional strategies and teaching styles easily. A webbased platform, called IDEAL (Integration and Dissemination of Electronic Assessment and Learning) was developed to offer teachers an environment for editing, managing and sharing of e-learning resources including materials, test items and instructional strategies. To promote the reusability and exchanging of learning resources, we adopt the e-learning standards such as SCORM for implementing and representing materials, IMS-QTI for tests, IMS-RES for testing results and IMS/LD for virtual classrooms. As a result, teachers can design, manage and maintain their own specific e-learning environment more easily and flexibly by the virtual classroom systems generated by the IDEAL system. It also makes the teacher’s learning resources and instructional strategies sharable to each other through the Internet.
This research aims to devise a conceptual model for describing the structure and process of web-based virtual classrooms, according to the learning design standard of IMS/LD specification [6]. Though the virtual classroom model was inspired by the CMI (Computer Managed Instruction) [7], extensions are considered to accommodate the interactions between individual learners and/or between a learner and a tutor. A web-based platform, called IDEAL (Integration and Dissemination of Electronic Assessment and Learning) was developed to offer teachers an environment for editing, managing and sharing of e-learning resources including materials, test items and instructional strategies. To promote the reusability and exchanging of learning resources, the IDEAL integrates the e-learning standards such as SCORM [8] for implementing and representing materials, IMS-QTI for tests and IMS-RES [9] for testing results and IMS/LD for virtual classrooms. Besides, a virtualclassroom engine is developed to instantiate and mange the virtual classroom activities according to the VC specification in run time. Through this system, instructors can develop a virtual classroom according to his/her teaching/learning strategies, and run the classroom with the help of the automated monitoring functions provided by the virtual-classroom engine.
KEY WORDS Web-based learning, virtual classroom, IMS-LD, learning flow management, Instructional resources sharing
1. Introduction The development of internet has imposed significant impacts on the design of educational and learning systems on the web. WWW has become one of the most important tools to build web-based learning environments. Among others, virtual classroom [1] is a teaching/learning model in distance learning. Virtual classrooms provide an effective and cost-saving alternative to face-to-face instruction, allowing instructors to reach more students in more locations than we would have without distance learning. Despite the lack of physical space, virtual classrooms allow students to exchange emotional support, information, and a sense of belonging, and students report that the virtual classroom provides a better learning
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2. A Conceptual Virtual Classroom Model As shown in Fig. 1, a virtual classroom (course) is composed of a structured set of “units”, of which every 267
elements that can be sequenced by the IMS Simple Sequencing elements. The elements can be learning objects, services and references to other environments. Learning objects are incorporated either by using an included schema (e.g., IMS QTI) or by referencing SCORM resources through the item elements. A service is a declaration of a service facility which has to be bound during instantiation of a run of a unit of learning. Currently, four kinds of services are provided in IMS-LD, which are send-mail, conference, index-search and monitor services, respectively. The service specification is extensible by name-spacing in additional services.
unit consists of a structured set of “activities”, of which every activity consists of a collection of “facilities”, including tools (communication tool, etc.) and resources. Both the unit structure and activity structure are hierarchical structures, where splits and joins are allowed. In the unit level, an instructor focuses on the decomposition of the target domain into a set of units, and identifying unit objectives and relations to one another and forming a hierarchical unit structure. Hierarchical and sequencing rules (including prerequisite conditions) can be specified in this level to control the delivery sequence of the course units. In the activity level, the instructor starts to design a set of teaching/learning activities for each unit, based on the participant roles and instruction/learning strategies. Finally, the instructor may select proper tools (services and/or resources), for example, an on-line discussion tool or e-mail services, that are needed to perform an activity.
A method in IMS-LD is a definition of the dynamics of a learning process. There is only one method allowed in an IMS-LD file. A method consists of one or more “play” which could be interpreted as the run-script for the unit of learning. Multiple plays in a method are interpreted as concurrent events. A play represents a “learning flow” in which a sequence of “acts” is performed during the learning process. An “act” specifies the activities that some participant roles have to take. Only one act in a play is active at any moment in run time (while previous acts can be visible to the user). An act represents a series of concurrent “role-parts”. A role-part relates exactly one “role” to exactly one type of “activity”. Figure 2 shows the relations among roles, activities and environments that contain learning resources and services.
Figure 1. The three-level virtual classroom model
3. The IMS Learning Design In this section, we give a brief introduction of IMS-LD. First, there are four IMS/LD ingredients needed to be specified in an IMS-LD specification, including “roles”, “activities”, “environments” and “method”. There are only two types of roles in IMS/LD, one is the “learner”, and the other is the “staff”, and you can expand the roles, forming hierarchical role sets. There are three types of activities in IMS-LD, including “learning activity”, “support activity” and “activity structure”. A learning activity is one for learners to get engaged. A support activity is often performed by staffs to give support for learners. It can get repeated for every user in the supported role (e.g. grade support). Finally, an activity structure allows us to construct a hierarchical activity structure, reusing learning activities, support activities and even other units of learning.
Figure 2. The relations among roles, activities and environments in IMS/LD. In summary, the conceptual mapping between IMS-LD to the learning process is depicted in Figure 3.
An environment is the supporting context that an activity is performed. An environment contains a sequence of 268
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Figure 3. A conceptual mapping between IMS-LD and learning process.
4. Mapping of Virtual Classroom Model to IMS-LD 4.1 Mapping of Unit Structure: An elementary unit is represented as a unit of learning in IMS-LD. The structure of units is represented as an activity structure of elementary units. The unit structure in the virtual classroom model is a hierarchical structure which is constructed from two basic blocks: sequential block and branch-merge block, respectively. The sequential block consists of a series of units that are arranged in a sequential order. The branch-merge block depicts a choice of units that are selected by users for at least a specific number of units set by the designer.
Figure 4. A sample of unit structure in a virtual classroom consisting of five elementary units. Note that there is only one act in the play, and two roleparts are specified in the only act, one for staff (teachers, etc.) and the other for learners (students, etc.). Therefore, all staff and learners are allowed to play roles in this virtual classroom. Nevertheless, specific roles can be assigned to specific learning activities within each unit by the designer of this virtual classroom.
For example, the following xml code segment represents in IMS-LD a virtual classroom consisting of five units, which consists of a branch-merge block of unit 1 and 2, and a series of units 3, 4 and 5, as shown in Figure 4.
4.2 Mapping of Activities Activities in the virtual classroom model can be packaged into higher-order activity structure of elementary activities. It is assumed that roles assigned to the activity structure apply to all the activities within it. Similar to unit structuring, there are also two basic packing blocks for activities: the sequential block and branch-merge block. An elementary activity corresponds to an activity (learning/support) in IMS-LD, while activity packs correspond to activity structures in IMS-LD. In the roleassignment phase, if multiple roles are assigned to the same activity, multiple role-parts will be generated for the same activity or activity structure.
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Step 3: For each elementary unit, give a plan on the activities according to some instruction/learning strategy, and have the activities be structured either sequentially or selectively. As to the activity structure of “selection” type, the choice may be selected manually or automatically by the system according to the state set by previous activities. In this case, we say that there is dependency between the two activities. In this step, the instructor determines the dependency between activities, which in turn determine the proper properties that should be maintained in IMS/LD. The other kind of state properties, such as counters, relates to the checking of triggering conditions of next activity. (The matching of properties on conditions can be handled by reasoning shell of expert system so that redundant matching on conditions for circumstances no longer desired is prevented.) At last, create an environment, including learning objects and services, for each activity.
4.3 Routing of Activities Routing of activities means the arrangement of a learning flow, which corresponds to the “play” in IMS-LD. Decisions of assignment of roles to activities and specification of the flow of activities are made in this phase. There are two routing schemes in the virtual classroom: the sequential routing and fork-join routing. Activities in a routing can be assigned to different roles. The sequential routing of activities depicts a series of activity (packs) to be performed in sequel; while the forkjoin routing depicts a parallel route of activities which are activated in a concurrent manner. A sequential activity routing in the VC model is mapped to multiple sequential “acts” components in IMS-LD, while a fork-join activity routing is mapped to a single “act” component with multiple role-parts in IMS-LD. 4.4 Mapping of Facilities.
Step 4: For each elementary unit, select activity structures and arrange their routing either sequentially or in parallel. Determine the roles for the corresponding activities. A variety of roles can be organized in a hierarchical structure. This enables the roles to be given activities as single group when appropriate, rather than the same activity needing to be given multiple times to each subrole. Synchronization points may exist within role-parts, inter role-parts in the same act or inter role-parts of different acts. In the first case, participants of the same role synchronize one another by joining the same activity; in the second case, participants of different roles synchronize one another by joining to the same activity in the same act. At last, participants of different roles synchronize one another by joining to the same activity in different acts.
Facilities in the VC model correspond to the environments in IMS-LD. An environment contains learning resources and services. While providing services is nothing more than an implementation issue, a generic service specification needs to specify parameters and resources related to the service. For example, in the mail service specified in IMD/LD, information about the receivers, email title and data need to be specified. Some services, such as monitor, need the implementer provides persistent memory for global properties. Extension is possible to allow more services to be encoded in an environment. 4.5 Association of Units with Activities In the VC model, only elementary unit can be associated with an activity block. Recall that each elementary unit is encoded as a unit of learning in IMS-LD. The association of units with activities (plus routing flows) can be done easily by associating with the unit of learning corresponding to the activity block
6. System Implementation A prototype system was implemented to test the feasibility of the virtual classroom model based on IMS/LD. This prototype is running on Tomcat 5.0 with a native XML database Xhive 6.0. The system architecture is shown in Figure 5. A virtual classroom designer with visual interface is developed to help instructors create and maintain the virtual classroom specifications. These XML specifications are stored in a native XML database Xhive 6.0. The XML IMS/LD Packer is aimed to collect the information provided by users through the Form Editing Interface, and packs the information according to IMS/LD specification. The information includes basic classroom information, unit structure, activity structure, routing information and environments. XML DOM API is adopted to transform the information into XML format by java codes.
5. Design Process of a Virtual Classroom The design of a virtual classroom based on IMS/LD can be top-down, bottom-up, or combining both. In the following, we present a top-down alterative to design a virtual classroom. Step 1: Determine the title, learning objectives and prerequisites of the virtual classroom. Step 2: Divide the course into a hierarchy of units. Units can be structured either sequentially or selectively as aforementioned. Assign learning objectives and prerequisites to each unit (a unit of learning in IMS/LD).
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Figure 5 The prototype system architecture. A prototype run-time engine (VC-Server Engine) based on java servlet is developed to instantiate a virtual classroom and delivers it to the user sides. The VC-Server Engine is aimed to do two tasks: (1). Instantiate a virtual classroom according to its specification and states, and (2). Monitor the running of learning flows in the virtual classroom, and responds properly by generating proper events according to the attributes and state change specified in the activities. The VC-Server Engine loads the VC specification file from the database, parses it and performs dynamic linking to the services and resources as specified. At last, it adopts the XSLT technique to generate a proper virtual classroom screen and delivers it to the client sides. The run time engine also monitors the run of the learning flows in the classroom, and stores all necessary property values so that the classroom can be restarted in a proper state. It is worthy to note that other IMS-LD engines like CopperCore [10] or Cow [11] are similar to our VC-Server engine and are more powerful in the supported level of the IMS-LD Spec. Therefore, we are planning to replace the VC-Server engine by a modified version of CopperCore to fit it in the IDEAL system. Figure 6 and 7 show the screenshots of the VC editing and unit structure editing, respectively.
VC Information Filling Form Resource Pool
Unit Structure
Figure 6. VC Unit Structure Edit screenshot. The elementary unit of learning is basically following the specification of IMS-LD. Therefore, creation of a unit of learning including creation of roles, activities, environments (tools and learning objects), and learning flows, as shown in Figure 7. In particular, IDEAL provides SCORM-compliant learning objects as well as IMS-QTI compliant assessment objects. Besides, learning objects and assessment objects can be embedded to each other seamlessly so that it is easy for the author to create a unit of learning that involves both material studying and testing in the IDEAL system.
As shown in Figure 6, an author of virtual classroom focus on devising a unit structure of the course and filling course metadata in the VC unit structure editing phase. Each elementary unit is attached by a unit of learning which can be selected from the resource pool that comprises all the learning resources, including units of learning, that are either public or private.
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Resource Pool
[3] S. R. Hiltz & B. Wellman, Asynchronous learning networks as a virtual classroom, Communications of the ACM, 40(9), 1997, 44 – 49.
Unit of Learning Activity Information
[4] D. Zhang, J. L. Zhao, L. Zhou & F. Jr. Jay Nunamaker, Can e-learning replace classroom learning? Communications of the ACM, 47(5), 2004, 75-79. [5] L. Neal, Virtual classrooms and communities. Proceedings of the international ACM SIGGROUP conference on supporting group work: the integration challenge, 1997, 81-90.
Unit of Learning Structure
[6] IMS Global Learning Consortium ： IMS Learning Design Information Model V1.0. Final Spec. (2003) [Online]. Available: http://www.imsglobal.org
Figure 7. Elementary Unit Edit screenshot.
[7] AICC: CMI Guidelines for Interoperability AICC Document NO. CMI001. (2001) [Online]. Available: http://www.aicc.org/.
7. Conclusion In this paper, we propose a conceptual model based for developing web-based virtual classroom, and implement this conceptual model with IMS/LD specification. The system is successful in integrating learning resources compliant to SCORM, IMS/QTI standards in the virtual classroom, enhancing feasibility, reusability and friendliness of the virtual classroom on the Web. As a result, teachers can design, manage and maintain their own specific e-learning environment more easily and flexibly by the virtual classroom systems generated by the IDEAL system. It also makes the teacher’s learning resources and instructional strategies sharable to each other through the Internet. Nevertheless, the services provided in the current system cover only a small set of all possible instruction/learning tools (e.g., the mail and BBS). More services such as conferencing and monitor are expected to be added in the future.
[8] ADL: The SCORM Content Aggregation Model V1.2. (2001) [Online]. Available: http://www.adlnet.org/. [9] IMS Global Learning Consortium ： IMS QTI/RES V1.1. (2000) [Online]. Available: http://www.imsproject.org. [10] CopperCore project website, http://coppercore.org/ last visited 2004. [11] T. Vantroys & Y. Peter, COW: A flexible platform for the enactment of learning scenarios, Proc. 9th Int. Workshop on Groupware, CRIWG 2003, Grenoble, France, 2003, 168-182 (Lecture Notes in Computer Science, 2806).
Acknowledgements This project was supported and founded by National Scientific Council, Taiwan under contract no: NSC 922520-S-130-001-.
References: [1] P. L. Chung, Online Learning and Virtual Classroom. J. Information and Education, 1999, 32-33. [2] S. R. Hiltz, Collaborative learning in a virtual classroom: highlights of findings. Proceedings of the 1988 ACM conference on Computer-supported cooperative work, 282-290.
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