Research Journal of Information Technology 3(1): 43-48, 2011ISSN: 2041-3114© Maxwell Scientific Organization, 2011Received: November 11, 2010 Accepted: December 08, 2010 Published: March 20, 2011

Corresponding Author: A.I. Obasa, Department of Mathematics, Statistics and Computer Science, Kaduna Polytechnic, Kaduna,Nigeria. Tel: +234 7034135440, +234 8028907216

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The Architectural Design of an Integrated Virtual Classroom System1A.I. Obasa, 2A.A. Eludire and 1Mbing Isaac

1Department of Mathematics, Statistics and Computer Science, Kaduna Polytechnic,Kaduna, Nigeria

2Department of Computer Science, Joseph Ayo Babalola University, Ikeji Arakeji,Osun State, Nigeria

Abstract: This study discusses the architectural design of an integrated system for the delivery of lectures ina virtual environment. The architecture and description of the system components are presented with thetechniques and recommendations for the implementation of the designed system. The system architecture ismulti-tier, modular, scalable and built for adaptability to database middleware suite. All functionalities withinthe application are delivered using Web Services, communicate via industry standard XML messaging andaccess is purely via a web browser. The virtual classroom application utilizes an operating system with facilitiesfor providing users web services, data and pre-processor hypertext with a simple and consistent User Interfacecorresponding to the tiers. With the object-oriented design method used in this application, three logicalcategories were identified for application objects, namely, objects that deal with presentation aspects of theapplication, objects that deal with the business rules and data, and objects that accept and interpret user requestsand control the business objects to fulfil these requests.

Key words: Application objects, client-tier, multiple-tier, user interface, web-tier

INTRODUCTION

Collaborative learning: (Collis, 1996; McNabb, 1994)stated that successful distance education systems involveinteractivity between teacher and students, betweenstudents and the learning environment, and amongstudents themselves, as well as active learning in theclassroom. Hiltz (1994) stated that collaboration andfeedback from other students make virtual classroom toovercome the absence of face-to-face communication.Most of the existing virtual classroom platforms lackcollaborative learning facility, which is an integralcomponent of teaching, and learning system.

Limited interaction: A good number of availableteaching and learning platforms use facilities like e-mail,wikis and bulletin board to provide students interaction.This approach is grossly inadequate as the teacher maynot be able to reply all mails that may be received andwhere received mails are replied the reply may not beimmediate. This process limits the amount and depth ofinteractions regarding course materials and procedures. Italso removes any feelings of connection between thestudent and instructor.

Lack of two-way real-time communication withfaculties: A good number of existing virtual classroomplatforms are asynchronous and do not facilitate two-way

real-time communication (Elluminate, 2007, 2008). Thereis need to incorporate many interactive features, for bothon-line and off-line use to facilitate the two-waycommunication between students and faculties, therebyalleviating the lack of sense of belonging of remotestudents.

One of the solutions to the above is to integrateasynchronous and synchronous learning platforms forvirtual teaching in higher Institution of learning. Thissolution requires an architecture that can resolve some ofthe limitations noted in achieving collaborative learning.The study therefore, has the objective of proposing anarchitectural design that foster the solution to thelimitations posed to collaborative learning, interactionsamongst learners, lack of two-way communication withfaculties and learner to learner’s interactions.

The proposed architecture comprises of fourinterrelated modules, namely, Application tiers,Application objects, Data Processing module and Coursemodule (Fig. 1) realised in multi-tier levels. Theimplementation of this architecture over web-basedservices has substantially resolved issues with theidentified limitations.

APPLICATION TIERS

The integrated virtual classroom system is a multiple-tiers application consisting of Client-tier, (CT), Web-tier

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Architecture of integrated virtual classroom

User 1 User 2 User 3

User 4 User 5 User 6User 7

User 8

Internet

Applicationtiers

Localhost: Moodle server(Asynchronous)

Applicationobjects

Data processingmodule

Course module

Launches request

Elluminate server(Synchronous)

Client tier (requestor)

Web tier (connector)

Enterprise information system(Database)

Clent -tierProvides user GUIBuilt with HTML. PHP, Java appletCommunicates through browsers

Web -tierProvides the dynamic content to usersPresent the data models to the clientAccepts and analysis the user’s inputsPasses user’s input to EIS for processingForward response back to users

Enterprise -tierStores the business object dataHandles business logicDeals with the business rules and data

Fig. 1: The architecture of integrated virtual classroom

Fig. 2: Architecture of multi-tier application

(WT) and Enterprise Information System-tier (EIS) asshown in Fig. 2. A tier can be anywhere in the network,local or remote; can be implemented with anyprogramming languages.

The client-tier application provides a Graphic UserInterface (GUI) to the end users, which is achieved usinga web browser, such as Internet Explorer, Opera orFirefox. The HTML and PHP with Java applet is used tobuild the client-side GUI page. A web server, Apache orInternet Information Server (IIS), which is bundled withMicrosoft 's Office server reference implementation, isused to serve the GUI page at the web-tier, and to providedynamic content HTML/PHP pages. The web-tier holdsdata models of the business data, presents the data modelsto the client through HTML/PHP pages, accepts and

analyzes the user's inputs, passes the user's request to theEnterprise tier for processing, and forward response backto the client. The WT handles the business logic and data.It communicates with the Enterprise Information Systemtier through appropriate protocols. A relational databaseMySQL version 5.2 and PHP are used to build the EIStier application.

The database should be of a powerful DBMStechnology that can handle application security. TheMySQL's Process Manager records and provides aviewable audit of all message transactions between webservices within the system. The front end is delivered aspure HTML to ensure that it is extremely lightweight andbrowser independent. The web-tier applicationcommunicates with the EIS-tier application through a

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Security managerAsynchronousLearningManager

SynchronousLearningManager

Data objects Business objects Presentation objects

Back-end (mySQL database)

Sign on security

User interface

User identification

Business process manager

User security audit trail

Back-End (MySQL)

Courseregistration

Courseadministration

Chatadministration

Synchronousadministration

Operating system (Windows)

Moodle

Fig. 3: Application objects

HTML/PHP Interface. The protocol is Internet Protocol(IP), which is transparent to the application developmentsince all these have been done on the Windows operatingsystem. This design architecture enables a greatflexibility, modularity and independence of the clientfrom the server application development.

APPLICATION OBJECTS

The object-oriented design method is used in thisapplication. The process of object-oriented design beginswith the identification of business objects, data, andpresentation objects and model each of them in software.At the highest level, the application objects can be dividedinto three logical categories (Fig. 3):

C objects that deal with presentation aspects of theapplication,

C objects that deal with the business rules and data, andC objects that accept and interpret user requests and

control the business objects to fulfil these requests.

Then the data objects are mapped to the business objects,then business objects to presentation objects.

DATA PROCESSING MODULE

One of the first decisions taken in this projectconcerns the tiers that the application uses. The chosenplatform is designed for multi-tier applications, and offersa lot of flexibility in choosing how to distributeapplication functionality across the tiers. In a Web-enabled application, such as this application, some tiersare always present. There is the client tier, that is, thebrowser. The browser communicates with the Web tier.Finally, the EIS or database tier holds persistent

Fig. 4: Data processing module

application data. However, there is a choice in whetherthe Web tier accesses the EIS resources directly, or goesthrough an Enterprise Java Bean (EJB) tier. The decisiondepends on the functionality, complexity, and scalabilityrequirements of the application in the real world. Sincesuch requirements can change as the application evolves,one goal for the design is to make it amenable tomigration to an EJB-centric approach therefore,this application is a multi-tier EJB-centricapplication. Figure 4 shows the architecture of anintegrated multi-tier application. It illustrates the flow ofdata through the application.

USABILITY SPECIFICATION

This application models a web-based student coursedelivery system. The application interface is presented tothe students through a hypothetic web site(http://localhost/students). The student interacts with theapplication using a web browser. The applicationpresents the student with a catalog of courses from whichthe student selects course offerings and register for theselected courses. New students are required to registerusing a combination of username and password. Thesystem notifies the student of course registration by aconfirmation email using JavaMail API. The student canalways make a query to see what courses he/she alreadyregistered earlier. When the student is ready, then,proceed to attend the lecture delivery either inasynchronous or synchronous mode.

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Assignments

Chats

Forums

Glossaries

Quizzes

Lessons

Blog

Wiki

User 1

User 2

User 3

Web

con

nect

orEl

lum

inat

e

Moo

de

User1

The usability specification is the key ways theapplication would be used. The kinds of functionalitywhich are available from the user interface of theapplication are:

C A common set of links or navigation bars on eachpage that provide the student with quick access tocommon navigational tasks.

C An organized view of the site’s contents through acategorized course catalog. A search mechanism toprovide students a way to locate courses based onkey-word descriptions.

C A master view of the catalog that lists courseofferings of interest to the student. This could be theresult of the user navigating through a catalogcategory or the outcome of a keyword searches.

C A detail view that describes the details of a particularcourse offering. Students can click on an offering inthe master view to zoom in on the details of thatparticular course.

C A chatting facility for student registered on aparticular course.

C Access to a forum where users (students andteachers) can exchange ideas on different issuesrelating to a given course.

C Access to submission and uploading of assignmentand subsequent access to the graded result.

Logical flow: A student connects to the application. If thestudent logs in, the user module maintains student's courseregistration information. It creates new student recordsand manages these records. Student records include suchinformation as student ID, name, password, address,phone and email address:

C The course module returns a list of courses available.The course catalog module searches the coursedatabase for a list of possible matches to the searchcriteria and renders the courses for the student user.

C The student views a specific course. The coursecatalog module also returns detail information aboutthe selected course.

C The student selects a course offering for registration.The registering client module creates a registeringcart for the student for the duration of the user’ssession.

C The student chooses proceed to registration optionand commits the course offering selections. Theregistration-processing module manages thisinteraction.

C The application determines whether the user islogged in and if not, either calls the student moduleto set up a new student or let him/her login.

C The application lets the user revise or cancel thecourse selections for registration. If the student

Fig. 5: Application functional modules

accepts, the registration processing logic logs theregistration, and sends a confirmation message byemail.

Application functional modules: Below is the list ofmodules that have been identified and theirresponsibilities:

C User registration module: The application tracksstudent information. This includes a student id andpassword and various types of contact information(email addresses, phone number, and so on). Studentinformation is in the database.

C Course registration module: The application allowsthe user to search for courses and be able to displaydetails of individual courses. The catalog includesdescriptions of individual course offerings.

C Assignment module: The application enablesstudents to upload written assignment to course-teacher. It also allows course-teacher to gradeassignment and publish the result to students.

C Chat module: A chat module is used for live-timediscussions. Chat is a very efficient way to discussthings in live-time.

C Glossary module: The application allows a flexibleway for students to add to present definitions (andmore) that can be linked through the entire class site.

C Elluminate module: This is used for synchronouslecture delivery.

C Lessons module: This feature allows for the additionof lessons that guide the student based on thestudent’s answers. It might be helpful to think of alesson as a kind of flowchart.

C Wiki: A wiki is similar to a blog (web log orjournal), except everyone can contribute, edit,comment, etc. In general, wiki posts are not approvedby the administrator, so the content can be built veryquickly.

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C Workshop module: This creates a workshop spacefor the class. It is used to facilitate a wide range ofpeer review options.

Figure 5 shows the interrelationship of the modulescorresponding to different tier of the application.

The modular decomposition of the application isreflected in the sub-modules in Figure 5 for theapplication’s high-level modules shown in Fig. 2.

THE IMPLEMENTATION TECHNIQUE

To keep development simple and under control of itssize, the following assumptions are made:

C Application design focuses on the student courseregistration interaction only. Administrationinteraction is done manually. Therefore, the EIS tierdatabase tables are pre-populated manually.

C For simplicity, only the courses offered in the comingsemester are stored in the Database. However, thereis no limit on number of students that can enrol.Theoretically, one or more instructors can offer acourse within the same semester, thus, no limit onstudents.

C There is no restriction on how many courses astudent can enrol (a reasonable student is limited byhis time and money).

C Instructor is not assigned to departments. C Once a course is registered, student cannot cancel it.

This can only be done by the administrator orinstructor through admin interface.

User interface: The user interface consists of a set ofscreens which is the total content delivered to the browserwhen the user requests an application URL. In otherwords, a screen is called whenever the user clicks on oneof the application’s URLs. A screen can be composed ofseveral components that constitute different parts of thescreen content. From the scenarios and functionspecifications discussed above, the following interrelatedset of screens is developed:

C Entry login screen: This screen is launched andaccessed from http://localhost/students/index.html,using a browser. It is a HTML page meant forcontrolling access to launching the virtual classroomapplication.

C Course category screen: Here a user can select theappropriate course for self-enrolment after successfullogon.

C Registered course screen: From this screen a userhas access to all the modules that relate to the coursein question such as chat, assignment, forum, etc asalready set up by the course administrator or teacher.

C Virtual classroom screen: From the RegisteredCourse screen a user can enter the virtual classroomby clicking on ‘Enter Virtual Classroom’ from wherehe/she can meet with the lecturer online in aprescheduled lecture.

Database schema: The back-end of an application is acollection of state with some rules on how the statechanges in response to user interactions. The applicationsystem maintains persistent data in MySQL databasetables. MySQL is an open-source relational database withcapability for middleware development. The databaseschema, the class diagrams and entity relationships havebeen omitted in this write-up to conserve space. A numberof modules use more than one table to store the neededdata in the relational database schema employed byMySQL.

CONCLUSION

In this research, the architecture for an integratedvirtual classroom for delivering lectures, issuing andcontrolling assignments, with chatting, choices andforums is proposed. The proposed architecture takescognisance of e-learning features such as the White board,Audio and Video features. The Video feature enables oneto transmit and receive video broadcasts with others in aclassroom session.

Open source facilities were used to develop anapplication that can give real-time lectures to students ina school system such as University, Polytechnic andCollege of Education. These open source facilities onasynchronous and synchronous platforms were combinedto give a blended real time virtual classroom that mimicsthe traditional face to face classroom.

RECOMMENDATION

Designing a virtual classroom is an enormous taskthat requires a lot of resources and time. Tertiaryinstitutions need to wake up and embrace ICT in lecturedelivery so that we can be able to train all our youths thatare seriously yearning for higher education.

The scope of this study was limited by the recoursesat the disposal of the researcher. It would be worthwhileif education agencies collaborate with universities to fundresearches on e-learning and virtual classroom instead ofspending money in constructing classrooms that willnever be adequate for the ever-increasing population.

Recognition given to certificates acquired throughdistance learning is still very low. Government may haveto come up with legislations and guidelines for theimplementation of e-learning and virtual classrooms sothat the certificates obtained through e-learning can beuniversally acceptable.

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ACKNOWLEDGMENT

The staff of the Computer Centre of KadunaPolytechnic were instrumental to the setup,implementation and testing of this web based system.Their contribution is hereby acknowledged in this study.

REFERENCES

Collis, B., 1996. Tele-learning in a digital world: Thefuture of distance learning. International ThomsonPublications, London.

Elluminate, 2007. Elluminate Live! Sessions. ElluminateInc., Canada

Elluminate, 2008. Moderator’s Guide. Elluminate Inc.,Canada.

Hiltz, S.R., 1994. The Virtual Classroom: LearningWithout Limits Via Computer Networks. AblexPublishing Corporation, Human-ComputerInteraction Series, Norwood, NJ.

McNabb, J., 1994. Telecourse effectiveness: Findings inthe current literature. Tech. Trend., 39(October):39-40.

MOODLE, 2005. Moodle for Teachers, Trainers andAdministrators. Retrieved from: www.moodle.org.