AN EDUCATIONAL SERVICES ARCHITECTURE TO SHARE

E-LEARNING RESOURCES

Shanshan Yang, Mike Joy

Department of Computer Science, University of Warwick, Coventry, U.K.

Teemu H. Laine

School of Computing, University of Eastern Finland, Joensuu, Finland

Keywords: e-Learning, Service oriented architecture, Educational services, Share resources, Interoperability,

discoverability, Reusability.

Abstract: Today many quality e-learning applications have been developed. They are widely used to cover varied

aspects of learning and teaching activities, such as developing learning materials, delivering learning

activities, and performing assessment tasks. Different applications rely on different technologies, require

different access characteristics, and are distributed on different servers across many organisations. However,

people cannot fully benefit from these valuable resources as they have not been shared effectively and

efficiently — there are many varieties of these resources, but these have not been properly described and

linked. In this paper, we propose a service oriented approach as a potential solution to better sharing and

reuse of e-learning resources, because it allows resources to be better discovered, accessed and linked.

1 INTRODUCTION

e-Learning resources refer to e-learning applications

and their content that support learning activities

including delivering learning activities, developing

learning materials and assessing learning

performances. The typical content these applications

handle include e-learning materials, assessment

submissions, marks, students’ records, and course

information (Zhou et al., 2009). In our research,

sharing e-learning resources means redistribution,

remix and reuse of currently available e-learning

systems and their supported content.

The rapid development of the Internet has

created opportunities to offer various e-learning

resources that rely on different technologies (Su et

al., 2005). However, there are barriers to sharing and

reusing these e-learning resources and include the

following problems in current practices:

 e-learning resources are difficult to be

discovered, as they are described poorly;

 e-learning resources are difficult to interoperate,

as they rely on different implementation

technologies; and

 e-learning resources are difficult to be reused, as

they have not been shared well enough.

We propose a novel service oriented architecture as

a potential solution for these issues, since it supports

the principles of discoverability, interoperability and

reusability. It allows resources to be outwardly

described and linked, so that they can be better

found, accessed and reused, without much work

being required for reimplementation.

In e-learning, interoperability means that varied

educational systems are connected so that requests

and responses can be transmitted using standard

messages, and passed around easily between those

systems (Bean, 2010). Discoverability means that

information about each application is described and

stored in a service registry, so that potential users are

able to search and compare available systems by

querying the service registry. Reusability means that

both students and teachers are able to reuse more

quality e-learning resources if they can be better

shared (Liu et al., 2007).

Many people from both industry and research

communities have attempted to apply service

technologies in e-learning (Zhou et al., 2009).

372

Yang S., Joy M. and H. Laine T..

AN EDUCATIONAL SERVICES ARCHITECTURE TO SHARE E-LEARNING RESOURCES .

DOI: 10.5220/0003302403720375

In Proceedings of the 3rd International Conference on Computer Supported Education (CSEDU-2011), pages 372-375

ISBN: 978-989-8425-49-2

 2011 SCITEPRESS (Science and Technology Publications, Lda.)

Figure 1: Educational Services Architecture.

However, current research is not comprehensive

enough as some of them have only addressed one

type of e-learning resource. For example, Simone et

al. (2005) have proposed a framework to share

learning objects using service technologies, and

Lucia et al. (2008) have developed a model to share

learning content together with systems which run

using the shared content. However, their work has

covered neither the sharing of students’ records nor

other applications to support assessment tasks.

Some current research about e-learning services

is not comprehensive and focuses only on the

principle of interoperability. For instance,

Phankokkruad and Woraratpanya (2009) have

proposed an architecture to allow e-learning services

to be better communicated. Sun and Fu (2005) have

also investigated the interoperability issues, but have

not mentioned other principles such as

discoverability or reusability.

3 EDUCATIONAL SERVICES

ARCHITECTURE

Service technologies have been successfully applied

in the business domain (Li et al., 2009), and we

argue that service technologies could be used to

share resources in e-learning. The diagram above

(Fig. 1) is the design of the educational services

architecture we are proposing. Our approach inserts

a layer between users and e-learning resource

providers – the Educational Services Bus (ESB).

There are four main components in the ESB

Service Registry, Message Exchanger, Data

Converter and Adapters.

- and these are supported

by networks and web servers.

3.1 Message Exchanger

The Message Exchanger acts as a data transport

engine. Its main purpose is to provide message

communications for interactions between service

clients and providers which carry educational data.

This component supports the service-oriented

principle of interoperability, and SOAP (Simple

Object Access Protocol) is one of the default

communication mechanisms to implement

interoperability. Apache Axis2 is a popular

technology which supports this (Lucia et al., 2008).

3.2 Data Converter

The main role of a Data Converter is to transform

the format of educational content in order to reuse it

for other purposes. This component supports the

AN EDUCATIONAL SERVICES ARCHITECTURE TO SHARE E-LEARNING RESOURCES

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principle of reusability in service technologies and

tackles problems caused by data format mismatch

(Kongdenfha et al., 2009). However, currently there

are few tools for converting the format of e-learning

content (Chung and Chao, 2007). Lack of existing

generic conversion tools can be partly explained by

the many different data formats for various e-

learning content. We suggest that the conversion

could contain two stages. The first converts selected

content to a transitional format, which is

subsequently changed to a specific format which the

target service can accept. For example, student

essays, which are generated as Word format, are first

converted to HTML, and then converted to XML

format before another service is able to process them

later on for detecting plagiarism (for example).

3.3 Service Registry

The Service Registry (also called Service Broker),

and publishes descriptions of services developed by

service providers. This component supports the

principle of discoverability. Many technologies have

been developed for the Service Registry, and most

service deployment platforms, such as the NetBeans

IDE or Eclipse supports service publication features

(Simone et al., 2005).

3.4 Adapters

The purpose of adapters is to support the principle of

interoperability. The Service Adapters enable

platform independence while deploying educational

services. They are connectors that map different

service interfaces and protocols into a common

model which can be accepted by the ESB. A Client

Adapter (also called a Client Gateway) receives

requests from clients and routes them to the

appropriate components in the ESB. Currently, there

is no single approach to the implementation of such

adapters, and a variety of technologies have been

adopted (Kongdenfha et al., 2009).

3.5 Discussion on ESB

The core component in our educational services bus

is the Message Exchanger, as it allows other

components to be connected together. Adapters are

an optional component in our ESB and they are

implemented only if the clients or services so

require. The integration of these two components

allows resources to be better interoperated.

Collaboration between the Message Exchanger,

Service Registry and the Adapters enable e-learning

resources to be better linked and discovered. The

cooperation between the Message Exchanger, Data

Converter and Adapters enables e-learning resources

to be better reused.

Much of the proposed architecture can be

implemented by using standard and open source

technologies (Sun and Fu, 2005). However, some

components such as the Data Converter and the

Adapters may require customised implementations

because they must cater for a wide variety of

different data formats and platforms (Kongdenfha et

al., 2009). We suggest that to find optimal,

generalisable solutions for implementing these

components requires further research.

3.6 Educational Services

Educational services in our research refer to

software components that provide certain

functionality to support certain learning and teaching

related tasks. For each service, its functionalities,

operations, data types and binding information are

specified in a service interface. In previous research

(Yang and Joy, 2009), we conducted a case study

within a university and proposed that there should be

nine types of educational services. The five services

we presented in Figure 1 are for illustrative

purposes. Each user can access more than one type

of service, and for each type of service there is more

than one type of user who can reuse it.

3.7 Use Case Example

The following is an example to explain how our

architecture supports the sharing of a typical

resource - plagiarism detection software.

Teachers require access to different plagiarism

detection applications for different purposes.

Sometimes, they need to handle different types of

coursework, sometimes they need to use different

methods to compare students’ assignments against

other students’ assignments, or against other

available web resources. Software for detecting

plagiarism already exists, including the Turnitin

(2010) products for essays, and JPlag (2010) and

Sherlock (Joy and Luck, 1999) for computer

programming assignments. However, users may not

know that they exist at all, and they cannot access all

of them easily since their user interfaces differ

substantially. By using our ESB, plagiarism

detection resources can be better described and

linked, so that teachers can choose appropriate

plagiarism detection software to reuse for different

assessment tasks from multiple service providers.

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The following explains how the various components

work together to support the task of detecting

plagiarism.

In our architecture, each plagiarism detection

tool is wrapped as a service — for example, the

Turnitin service, the JPlag service and the Sherlock

service. Details about each service are stored and

published in the Service Registry. Teachers will first

send a request to use a plagiarism detection service

to the Message Exchanger, which in turn will

contact the Service Registry, and return a number of

available services with descriptions. Users can then

make selections simply between these services

depending on their needs. The Message Exchanger

will pass messages containing student assignments

to the service that has been selected. The selected

service will then process the assignments and return

the detection results to users via the Message

Exchanger. By using the Data Converter in the ESB,

the format of the coursework can then be converted

so that it can be easily reused in any plagiarism

detection application. As users might access these

plagiarism detection services in different locations at

different times, and these services might be hosted

on different servers by different providers, the

current users and available services will change

dynamically over time. For these reasons, we also

suggest that both Service Adapters and Client

Adapters should be adopted in our ESB.

4 CONCLUSIONS

AND FUTURE WORK

This paper has proposed the design of our

educational services architecture, and has also

highlighted potential problems our service approach

can solve in current e-learning practices. In the near

future, we plan to implement a part of the proposed

architecture and conduct an experiment to evaluate if

our service approach is actually feasible, in order to

better support our research question: how could we

share e-learning resources effectively and efficiently

using services technologies?

REFERENCES

Bean, J., 2010. SOA and Web Services Interface Design:

Principles, Techniques, and Standards, Morgan

Kaufmann. Amsterdam.

Chung, J., Chao, K., 2007. A View on Service Oriented

Architecture, International Journal on Service-

Oriented Computing and Applications, 1(2), pp.93-95.

Joy, M. S., Luck, M., 1999. Plagiarism in Programming

Assignments, IEEE Transactions on Education, 42(2)

pp. 129-133.

JPlag, 2010. https://www.ipd.uni-karlsruhe.de/jplag/, (29

Sep 2010).

Kongdenfha, W., Motahari-Nezhad, H., Benatallah, B.,

Casati, F., Saint-Paul, R., 2009. Mismatch Patterns and

Adaptation Aspects, IEEE Transactions on Services

Computing, 2(2), pp.94-107.

Li, J., Wang, Y., Zhang, J., Zhang, Z., 2009. A Web

Service Adapter with Contract Oriented Methodology,

IEEE Conference on Computer and Information

Science, pp.1144-1149.

Liu, J., Wu, Y., Zhao, W., 2007. Modelling Learning

Contents Based on Web Services, International

Conference on Next Generation Web Services

Practices, pp.135-140.

Lucia, A., Francese, R., Passero, I., Tortora, G., 2008. A

Service Oriented Collaborative Distributed Learning

Object Management System. Lecture Notes in

Business Information Processing, Springer Berlin.

Phankokkruad, M., Woraratpanya, K., 2009. Web services

for Learning Management Systems. International

Conference on Communication architecture, pp.403-

408.

Simone, L., Fabio. C., Sean. W., Rubens. N., Saulo. V.,

2005. Integrating Repositories of Learning Objects

Using Web-Services to Implement Mediators and

Wrappers, International Conference on Next

Generation Web Services Practices, IEEE Computer

Society.

Sun, L., Fu, Y., 2005. Interoperability for Elearning

Services Management and Provision. International

Journal of World Wide Web, Springer. Netherlands.

Turnitin, 2010. http://turnitin.com/static/index.html, (29

Sep 2010).

Yang, S., Joy, M., 2008. SOA Services in Higher

Education, International Conference on Education and

Educational Technology, pp. 145-150.

Yang, S., Joy, M., 2009. Designing E-learning Services: A

Case Study, iJAC 2(4), pp. 35-43.

Zhou, D., Zhang, Z., Zhong, S., Yao, Y., Zhang, H., 2009,

The study of service oriented architecture of E-

learning resources and personalized service model.

International Conference on Machine Learning and

Cybernetics, 6, pp. 3591-3594.

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