TESYS: E-LEARNING APPLICATION BUILT ON A WEB

PLATFORM

Burdescu Dumitru Dan

Software Engineering Department, Faculty of Automation, Computers and Electronics, University of Craiova,

Bvd. Decebal, Nr. 107, 200440, Craiova, Dolj, Romania

Mihăescu Marian Cristian

Software Engineering Department, Faculty of Automation, Computers and Electronics, University of Craiova,

Bvd. Decebal, Nr. 107, 200440, Craiova, Dolj, Romania

Keywords: Web platform, e-learning application.

Abstract: This paper presents a Web platform on which we developed an e-Learning application. The platform

represents a web framework in which web applications may be developed. On the platform an e-Learning

application is deployed. The e-Learning application brings together professors and students in a

collaborative environment managed by secretaries and supervised by administrators. This paper introduces a

novel Web application frame based on MVC. This frame separates the business logic from the view and

model. Employed technologies, software architecture and software development process improve and

ensure the application maintainability, scalability and performance.

1 INTRODUCTION

The main goal of the application is to give students

the possibility to download course materials, take

tests or sustain final examinations and communicate

with all involved parties. To accomplish this, four

different roles were defined for the platform:

sysadmin, secretary, professor and student.

The main task of sysadmin users is to manage

secretaries. A sysadmin user may add or delete

secretaries, or change their password. He may also

view the actions performed by all other users of the

platform. All actions performed by users are logged.

In this way the sysadmin may check the activity that

takes place on the application. The logging facility

has some benefits. An audit may be performed for

the application with the logs as witness. Security

breaches may also be discovered.

The overall activity of users represents valuable

data. This data may be off-line analyzed using

machine learning or even data mining techniques

such that important conclusions may be obtained

regarding the quality of service for the application.

The quality of service may have two indicators: the

learning proficiency of students and the capability of

the application to classify students according to their

accumulated knowledge.

A statistics page is also available. It presents

the number of users that entered the application, the

total number of students, and the number of students

with and without activity and other information that

gives an overall view on the activity on the

application.

Secretary users manage sections, professors,

disciplines and students. On any of these a secretary

may perform actions like add, delete or update.

These actions will finally set up the application

such that professors and students may use it. As

conclusion, the secretary manages a list of sections,

a list of professors and a list of students. Each

discipline is assigned to a section and has as

attributes a name, a short name, the year of study

and semester when it is studied and the list of

professors that teach the discipline which may be

maximum three. A student may be enrolled to one or

more sections.

The secretaries have also the task to set up the

structure of study years for all sections. The

structure of a study year is made of a list of periods.

315

Dumitru Dan B. and Marian Cristian M. (2006).

TESYS: E-LEARNING APPLICATION BUILT ON A WEB PLATFORM.

In Proceedings of the International Conference on e-Business, pages 315-318

DOI: 10.5220/0001424803150318

 SciTePress

All periods that define the study year are disjunctive

in time and are characterized by a name, start date

and end date. For each period there are also set up

the exams that may be taken and the grants that are

needed. The way of defining what the student can do

and when proved to be very flexible and easy to

understand and use.

The secretaries have the possibility of searching

students using different criteria like name, section,

year of study or residence. The secretaries have a

large set of available reports regarding the student’s

status. Among them there is a list of students who

took all exams, a list of students who requested grant

for taking an exam one more time and many other

reports specific to secretary work.

The main task of a professor is to manage the

assigned disciplines while s discipline is made up of

chapters. The professor sets up chapters by

specifying the name and the course document. Only

students enrolled in a section in which a discipline is

studied may download the course document and take

tests or examinations. The manner of creating tests

and exams is intended to be flexible enough for the

professor.

All tests and exams are taken under time

constraints. For each chapter the professor sets up a

number of seconds necessary to answer questions

that chapter. When a test or exam is taken all the

seconds are summed thus obtaining a maximal

interval of time in which the student has to finish the

test. The elapsed and remaining time are managed

on server side and presented to the student after each

answered question.

The professor has also enough flexibility for

creating and editing questions. A question may

contain pictures, thus equations, formulas or other

graphics may be imbedded into it.

Students may download only course materials

for the disciplines that belong to sections where they

are enrolled. They can take tests and exams with

constraints that were set up by the secretary through

the year structure facility.

All users must authenticate through username

and password. If the username and password are

valid the role of the user is determined and the

appropriate interface is presented. The platform

assigns a set of actions that the user may perform.

Each time a user initiates an action the system

checks if that action allowed. This approach ensures

security at user’s level and makes sure that a student

may not perform actions that are assigned to

professor, secretary or sysadmin users.

A history of sustained tests is kept for all

students. In fact, the taken test or exam is fully saved

for later use. That is why a student or a professor

may view a taken test or exam as needed. For each

question it is presented what the student has

checked, which was the correct answer, which was

the maximum points that could be obtained from

that question and which was the number of obtained

points. At the end it is presented the final formula

used to compute the grade and the grade itself.

Besides these core functions for on-line testing

other ones are implemented or currently under

development. A message board is implemented for

professors, secretaries and students to ensure peer-

to-peer communication. This facility is implemented

within the platform such that no other service (e.g.

email server) is needed.

The logging facility that is mainly used by

sysadmin is transparently implemented for all users

(secretaries, professors and students). Whenever one

of them performs an action (e.g. a student starts or

finishes an exam) that action is recorded for later

use.

2 SOFTWARE ARCHITECTURE

OF THE PLATFORM

Many issues appear when applications contain a

mixture of data access code, business logic code,

and presentation code. Such applications are difficult

to maintain, because interdependencies between all

of the components cause strong ripple effects

whenever a change is made anywhere. The Model-

View-Controller (MVC for short) design pattern

solves these problems by decoupling data access,

business logic, and data presentation and user

interaction.

The e-learning platform consists of a

framework on which a web application may be

developed. On server side we choose only open

source software that may run on almost all

platforms. To achieve this goal Java related

technologies are employed.

The architecture of the platform allows

development of the e-learning application using

MVC architecture. This three-tier model makes the

software development process a little more

complicated but the advantages of having a web

application that produces web pages in a dynamic

manner is a worthy accomplishment. The model is

represented by DBMS (Data Base Management

System) that in our case is represented by MySQL.

The controller, which represents the business

logic of the platform, is Java based, being build

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around Java Servlet Technology. As servlet

container Apache Tomcat 5.0 is used.

This architecture of the platform allows

development of the e-learning application using

MVC architecture. This three-tier model makes the

software development process a little more

complicated but the advantages of having a web

application that produces web pages in a dynamic

manner is a worthy accomplishment. The model is

represented by DBMS (Data Base Management

System) that in our case is represented by MySQL.

The controller, which represents the business logic

of the platform is Java based, being build around

Java Servlet Technology. As servlet container

Apache Tomcat 5.0 is used.

The view tier is template based, WebMacro

technology being used. WebMacro is also a Java

based technology the link between view and

controller being done at context level. The

separation between business logic and view has

great advantages against having them together in the

same tier. Once web developer has set up the

business logic, web designer can independently

work on the view. This decoupling makes

development process more productive and safer.

One of the biggest disadvantages of having business

logic and view together is the lack of modularity that

brings problems in application testing and error

checking.

Tesys application is an implementation of

platform to which new data sources, business logic,

and data views may be added.

The business logic of the application uses Java

classes. There are four levels of dependency

between classes: servlets, actions, managers and

beans.

Servlets level has so far two of them:

MainServlet and DownloadServlet.

The MainServlet can be seen as the main gate

of the application. Its main purpose is to check

whether the request may be fulfilled or not from

user’s role point of view. By default, a user is a

visitor and may execute only non-critical actions.

The MainServlet redirects visitor users to welcome

page where they are supposed to provide a username

and a password in order to login. The second level

of classes in the dependency tree has the action

classes that effectively take care of the requests. The

main action classes are Login, Logout, Sysadmin,

Secretary, Student and User.

Secretary class codes the actions that may be

run by secretary users. There are 64 defined actions

that code sections, professors, students, disciplines,

exams, grants and feedback management. Ten

actions implement secretary’s communication with

students and professors.

Professor class codes the actions that may be

run by professor users. There are 46 defined actions

which code disciplines (chapters, test and exam

questions), students, grants management. Professors

to communicate with students and secretaries use ten

actions.

Student class codes the actions that may be run

by student users. There are 51 defined actions which

code test and exam taking and displaying,

maintenance of profile data, communication with

secretaries and professors, request of grants to take

another examination and fill in feedback forms.

The third level of classes in dependency tree

has the manager classes that are extensively used by

action classes. Manager classes are in close

relationship with the database relations. We have

implemented twelve manager classes for the most

important relations. A manager class implements all

needed operations on a specific relation.

The last level of classes consists of bean

classes. These classes are used mainly in manager

classes and are in one to one correspondence with

the relations from the database. In fact, for each

relation there was defined a bean class.

The model is implemented in MySQL and

consists of 21 relations. Among the most important

ones are: user, role, userrole, usersections, sections,

questions, testquestions, examquestions, testresults,

examresults, messages, activity.

This database model is used as a completely

passive holder of the data that is manipulated

entirely by the controller. The model is totally

unaware of the existence of either the view or the

controller and of its participation in MVC

architecture.

The view uses WebMacro templates. Similarly

to action classes in Controller, the templates are

organized into folders based on the role of the user

that will have them displayed.

3 EXPERIMENTAL RESULTS

The platform is currently in use on Windows 2003

Server machine. The setup process consists of two

stages. After all needed software is installed (JDK

1.4.2, Apache Tomcat 1.5 and MySQL) the

application is deployed. The database structure is

created and a sysadmin user is added.

After the setup process finishes the sysadmin

user logs in and creates a secretary user. The

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317

secretary adds the sections, professors, disciplines

and students.

After secretary finishes the setup process

professors may start to manage their assigned

disciplines. Each professor defines the chapters of

each discipline by setting up the name of the chapter

and the corresponding course document. After

adding a chapter, test and exam questions are also

added.

Once the platform is running and all sections,

disciplines, course documents and questions are in

place, students can also start using the application.

This means they can download course materials and

take tests and exams.

As a privilege of the sysadmin and professor,

they can monitor the activity of every student for

each discipline. This monitoring facility provides a

good view over the activity of the student. The

system keeps tracking when the student logged in,

how much time he spent until logging out, which

courses were downloaded, how many tests were

taken and at what chapters. Table 1 presents the

activity of a student regarding a certain discipline.

Table 1: Activity of a student regarding a certain

discipline.

Property Value

Number of

downloaded chapters

Number of tests from

chapter 1 (grades)

10 ( 9.5, 8, 7.5,6.2,3.3,

9.8,6.5,8.3, 7.1,8.9)

Number of tests from

chapter 2 (grades)

9 ( 8.5, 9, 7.2,5.9,7.3,

9.8,6.5,8.3, 7.1)

Number of tests from

chapter 3 (grades)

10 ( 9.8, 8, 7.9,6.9,7.9,

9.2,7.5,5.3, 8.1,8.9)

Number of tests from

chapter 4 (grades)

11 ( 4.5, 5, 7.8,6.9,5.8,

9.5,6.8,8.7, 7.8,7.6)

Exam grade 8.6

So far, the system was proven to be solid

enough with good response time.

4 CONCLUSIONS AND FUTURE

WORK

This paper presents how a web application for

computer based testing was designed and

implemented. The design of the platform is based on

MVC model that ensures the independence between

the model, the controller and the view.

These choices were very carefully done, only

open source software being used. All queries comply

SQL Standard so that the DBMS may be changed

without interfering the controller and the view part.

The goal of the platform is to create an

environment in which students can take tests or

exams at different disciplines. Sysadmin, secretary

and professors manage the entire infrastructure of

the application. The task of the secretary is to

manage the general infrastructure consisting of

sections, professors, disciplines and students.

Professors have to manage their assigned disciplines

which means editing questions for testing or

examination purposes.

This platform is currently in use and has three

sections and at each section four disciplines. Twelve

professors are defined and more than 650 students.

At all disciplines there are edited almost 2500

questions. In the first month of usage almost 500

tests were taken. In the near future, the expected

number of students may be close to 1000.

Recording student’s activity under these

circumstances provides great information regarding

user traffic. After six month of usage there are more

than 40,000-recorded actions. Our next concern is to

employ different methods of analyzing the traffic in

order to create usage patterns and keep the

application in good shape.

Other facilities are under continuous

development and will give all users the possibility to

create a better collaborative environment.

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