INTEROPERABILITY IN PEDAGOGICAL eLEARNING

SERVICES

Ricardo Queirós

CRACS/FCUP & DI-ESEIG/IPP, Porto, Portugal

Keywords: eLearning, Interoperability, Service Oriented Architectures.

Abstract: The ultimate goal of this research plan is to improve the learning experience of students through the

combination of pedagogical eLearning services. Service oriented architectures are already being used in

eLearning but in this work the focus is on services of pedagogical value, rather then on generic services

adapted from other business systems. This approach to the architecture of eLearning platforms raises

challenges addressed by this work, namely: conceptual modeling of the pedagogical eLearning services

domain; interoperability and coordination of pedagogical eLearning service; conversion of existing

eLearning systems to pedagogical services; adaptation of eLearning services to individual learners. An

improved eLearning platform will incorporate learning tools adequate to the domains it covers and will

focus on the individual learner that uses it. With this approach we expect to raise the pedagogical value of

eLearning platforms.

1 MOTIVATION

The majority of the eLearning platforms available

today follow a component-oriented architecture.

These systems assemble a collection of generic tools

- such as forums or multiple choice quizzes - that are

considered to be useful for all subjects. Despite their

success, they have also been target of criticism that

led to recent initiatives to adapt Service Oriented

Architecture (SOA) to eLearning. The pressure to

adopt SOA in eLearning is mostly fuelled by

managerial needs of academic institutions, rather

than pedagogical concerns of teachers. In some

cases is an internal need, of combining

infrastructures of autonomous departments with

different responsibilities within an academic

institution. In other cases results from external

pressure, of linking with other institutions in order to

offer join eLearning programs.

An alternative view of eLearning services is to use

them to extend the pedagogical features of

eLearning platforms. Traditionally, these features

are added to eLearning systems by integration of

new components. These components are system

specific and tend to be very general, in order to be

reusable in as many situations as possible. As for

components, services are easy to add and replace in

a system but, unlike components, services are easy

to restructure to implement new processes, usually

business processes. This approach can also be

extended to learning processes in order to create an

instructional environment more adapted to the

student needs and requirements. For instance,

existing eLearning platforms do not provide specific

tools for solving programming exercises in computer

science courses, playing business games in

management courses, or simulating a human patient

in life sciences courses. These tools would be too

specific to incorporate in a eLearning platform. Even

if they could be provided as pluggable components,

the burden of maintaining them would be prohibitive

to institutions with few courses in those domains. On

the other hand, a programming exercise evaluation

engine, a business game engine or a patent simulator

can provide their services to many eLearning

systems. In turn, these services can be clients of

other services, such as repositories of specialized

Learning Objects (LO), or generators of LO. The

selection of LO can be mediated by another service

that adapts its results to the needs and preferences of

students.

The ultimate goal of this work is to improve the

students’ learning experience through the

combination of pedagogical eLearning services. To

achieve this goal it is necessary to fulfill both

abstract and concrete requirements. Firstly, it

Proceedings of ICEIS 2009

11th International Conference on Enterprise Information Systems

requires a categorization of types of pedagogical

eLearning services to support the definition of an

interaction model for this class of services.

Secondly, it requires also a reasonable number of

actual pedagogical eLearning services, both general

– such as repositories of learning objects – and

specialized – such as evaluator of programming

problems.After returned the manuscript must be

appropriately modified.

2 STATE OF THE ART

The evolution of eLearning systems comprises the

last two decades. In their first generation eLearning

systems were developed for a specific learning

domain and had a monolithic architecture (Dagger,

2007). Gradually, these systems evolved and became

domain-independent, featuring reusable tools that

can be effectively used virtually in any eLearning

course. The systems that reach this level of maturity

usually follow component oriented architecture in

order to facilitate tool integration. An example is

Learning Management Systems (LMS) that integrate

several types of tools for delivering content and for

recreating a learning context.

The present generation values the interchange of

learning objects and learners' information through

the adoption of new standards that brought content

sharing and interoperability to eLearning. Standards

can be viewed as "documented agreements

containing technical specifications or other precise

criteria to be used consistently as guidelines to

ensure that materials and services are fit for their

purpose" (Bryden, 2006). In the eLearning context,

standards are generally developed for the purposes

of ensuring interoperability and reusability in

systems and in the content and meta-data they

manage. In this context, several organisations (IMS,

IEEE, ISO/IEC) have develop specifications and

standards in the last years (Friesen, 2005). These

specifications define, among many others, standards

for eLearning content (IMS-CP, IMS_MD, IMS-

QTI) and interoperability (IMS-DRI) (Simon, 2005).

These integrated environments have been

successfully used to leverage the advantages of

ICTs, but have also been target of criticism (Dagger,

2007). Examples of these criticisms are the

excessive focus on content, the lack of support to

specific needs and the difficulty to integrate with

other eLearning systems. These shortcomings

triggered the appearance of initiatives (Smythe,

2003), (OKI, 2005), (Wilson, 2004) to adapt Service

Oriented Architecture (SOA) to eLearning. These

new frameworks and APIs contributed with the

identification of service usage models and are

grouped into logical clusters according to their

functionality (Aguirre, 2006).

The service oriented architecture is appropriate in

contexts where exists a combination of several

different components that needs flexibility in their

configuration. The communication between these

components is based generally on web services

(WS). The Web Service Description Language

(WSDL) provides a description of how to use a WS

but not how several WSs cooperate to achieve a

given goal. This issue is handled by several

specifications that use orchestration (WS-BPEL,

2007), (Weerawarana , 2007) and/or choreography

(WS-CDL, 2004) to define an interoperable

integration model. This model facilitates the

expansion of automated process integration and the

management of the workflow within services (Feier,

2005).

Personalised adaptive learning is also a new area of

research at the crossroads of the Intelligent Tutoring

Systems (Wenger, 1987), Adaptive Hypermedia

(Brusilovsky , 2001) and Multi-agent systems (Lin,

2005). In adaptation and personalisation the user

plays a fundamental role in the system’s design.

Representing user profile data is just one step (IMS-

LIP, 2001), (PAPI, 2000) of the process. Their

semantic differences raise several interoperability

issues when they need to be distributed (Aroyo ,

2006). It should be noted that adaptive learning has

not yet been adequately addressed in any eLearning

specification or standard (Manjón , 2007) and is one

of the main topics of research groups, such as,

aDeNu and e-UCM.

Apart from the user model, another important topic

is the instruction model that specifies the

navigational design ("flows") for an adaptive

hypermedia application. Several specifications

(IMS-SS, 2003), (IMS-LD, 2003) were create to

deal with the design of pedagogical activities, but

designing more complex adaptive behaviour are still

hard to achieve (Aroyo, 2006).

3 OUTLINE OF OBJECTIVES

The main goal of this work is to improve the

students learning experience through the

combination of pedagogical eLearning services. The

tasks described in the following sub-sections

contribute to this goal, each one with specific

objectives.

3.1 Conceptual Model

The main objective in this task is to formalise a

conceptual model of the domain of pedagogical

services. We will start by identifying and

characterising the main concepts in this domain -

services and actors - and the relationship among

them. We will study the service genres identified by

existing eLearning frameworks (Smythe, 2003),

(OKI, 2005), (Wilson, 2004) and extend then to

pedagogical services. Examples of pedagogical

services are authoring tools, evaluation engines,

specialised repositories, etc. For instance, the class

of authoring tools includes Integrated Development

Environments (IDE) commonly used for developing

computer programs. A system of this type can be

extended to provide an authoring service to a

pedagogical process for learning a computer

programming language. The IDE will consume other

pedagogical services: it will load programming

problems from a specialised repository, will submit

the learner's solution to an evaluation engine and

report results to a Learning Management System

(LMS) with a grade book. In this model we intend to

characterise classes of pedagogical eLearning

systems by the type of services they provide and

consume.

We will focus on pedagogical services but we will

also cover other support services required by any

SOA platform (e.g. security). The model will precise

also the role of actors - students, teachers, and staff -

with relation to services they use. We expect to

define this conceptual model using Web services

ontologies (OWL, 2007).

3.2 Interaction

In this task the main objective is to specify

interoperation of pedagogical eLearning services.

We will start by studying the classic models of

integration, with emphasis on service based

integration. Based on our early work implementing a

repository of Learning Objects (LO) as a service, we

will consider different web services flavours, namely

SOAP and REST. The former are based on W3C

specifications but are more complex and require

specialised SOAP engines. The latter have an

informal specification, are straightforward to

implement and more efficient. Service definition in

the WS-SOAP framework is based on the WSDL

language. The current version of this language has

already support for semantic annotations using RDF

- a standard XML language used for representing

OWL ontologies. This fact is a strong point in

favour of SOAP. Nevertheless, we will seek

alternative service representations with support for

semantic descriptions, compatible with REST.

Using semantic Web methodologies and associated

technologies we will explore different ways to

improve eLearning services. Services may use a

commonly agreed semantic based language for

sharing concepts. Users can describe their situation

(goal of learning, previous knowledge, etc) and

services may perform semantic querying for the

suitable learning material. Information may be active

delivered (based on personalised services) to create a

dynamic learning environment integrated in the host

institution business processes. Learning Objects

(LO) are distributed on the web, but they may be

linked to commonly agreed ontologie(s) to help the

discovery of what the LO is about.

Service discovery and coordination (e.g.

orchestration, choreography) are main issues that we

have also to address. The main goal is to enable

semantic mapping and the coordination of eLearning

services. For coordinating eLearning processes we

will explore two alternatives: orchestration and

choreography. The former is a standard central

coordination approach; it can be implemented using

Business Process Modelling (BPM) engines that

perform orchestration running process descriptions

written in languages such as BPEL. The latter is a

self coordination approach that has not reach the

same level of maturity.

The expected result of this task is a model for

interaction among pedagogical eLearning services.

This model will build on the characterisation of

services defined by the previous task.

3.3 Integration

As proof of concept, we will need a critical mass of

services to implement the previously achieved

models in a specific learning domain - the automatic

evaluation of programming problems. Moreover, to

test the previous approaches, such as semantic web

and web adaptivity, we need actual eLearning

services with true pedagogical content. In this task

we will recast existing eLearning systems as

services. In the defined domain - the automatic

evaluation of programming problems - we want to

support all the life cycle of a programming problem,

since its creation, searching, solving and evaluation.

We will use different services types, covering the

categorisation resulting from the first task, based on

existing eLearning systems. Candidates to provide

these services are:

 a repository of learning objects - e.g.

 crimsonHex (Leal and Queirós, 2008) - to

provide persistent storage, search and

download of LO and related meta-

information;

 an evaluation engine - e.g. Mooshak (Leal and

Silva, 2008) - to evaluate and produce

feedback to the learners problem’s attempts.

 An LMS (e.g. Moodle) - to manage and retrieve

the exercises to the learners.

Our novel idea is to integrate an IDE in the actual

infrastructure. This integration will provide the

student an interactive and assisted environment in

the resolution of problems. This idea resulted from

the need to address the lack of integration of

intelligent codification environments in the process

of solving programming exercises. The integration

includes the following steps: study of IDEs "open

source" (Eclipse, NetBeans, etc.) and the several

integration levels of components in the IDEs

platforms, namely: by invocation, by sharing data,

through API's (Application Programming Interface),

based in UIs (User Interface) and through PDEs

(Plug-In Development Environment).

In this task we expected to recast existing eLearning

systems as services, as well as create brand new

services identified in the first task. The recasting of

existing systems as services will be the least

intrusive possible in order to share and support the

previously created models.

3.4 Adaptability

This task's objective is to use approaches from

hypermedia adaptability to enhance pedagogical

eLearning services. Adaptability is typically used

within content or to select among alternative

contents. In this setting, adaptability can also be

used to dynamically combine eLearning services. To

address the lack of focus on the learner, a major

problem in existing component-based eLearning

systems, we will adapt services to the requirements

of students and, ultimately, to provide adaptability as

a service itself, that adds value to eLearning

processes. This challenge includes and expands the

goals of web adaptivity, since we are interested in

adapting not only the web user interface, but also

functions exposed by web services. Pedagogical

services will provide functions for collecting

information on students and their activity. This

stream of information will be used for understanding

their behaviour and predicting their needs., using: 1)

a data-warehousing service for collecting and storing

relevant information; 2) monitoring tools for

computing indicators (metrics) and infer measures of

success of the learning process; and 3) adaptation

services that use the activity information that

predicting models for other pedagogical eLearning

services.

As said before, we will try to provide adaptability

itself as a pedagogical eLearning service,

independent from domain specific services. The

expected result of this task is a set of mechanisms

for coordination of the learning process based on the

profiles of the students, adjusted to their needs and

preferences.

Other research path is the articulation and dynamic

sequencing of instructions based on existing

standards for sequencing and navigation (IMS-SS,

2003), (IMS-LD, 2003). These specifications aims to

provide to the teachers mechanisms for coordination

of the educational instructions based on students'

profile making the instruction more dynamic and

flexible. In this research path we will study the

existing standards for sequencing and navigation and

implement dynamic sequencing in a LMS.

3.5 Evaluation

In a final task the objective is to validate the

proposed approach by testing the conformance to the

initial requirements - interoperability and

adaptability. A set of pedagogical process for

programming language instruction will be created to

support this evaluation. Other specific domains will

be considered, such as, managing remote electronics

laboratory activities that uses specific hardware

resources (micro-controllers, oscilloscopes, among

others). The evaluation will be characterised by a

definition of set-up live experiments with real

students, enrol within courses of the domains

described early. This phase will allow us to validate

our work in production scenarios and measure the

adhesion of the students to the eLearning platform.

4 EXPECTED OUTCOME

The aim of this PhD work-plan is the improvement

of eLearning platforms based on service oriented

architectures by focusing on the learner and on the

learning subjects. It addresses the fundamental

problems of creating such service oriented

eLearning infrastructure - interoperability and

adaptability - and the production of a collection of

services on which to base eLearning platforms,

which will be used as test bed for validation and

future research. We envision a federation of

pedagogical eLearning systems, including those

already in use nowadays, providing their services to

several eLearning platforms. These pedagogical

services will add value to the learning process,

contributing either with content/context to a specific

learning domain, or with its adaptation to the needs

and preferences of a particular student. These

services interoperate seamlessly, ensure security and

will be reusable in different learning processes.

5 CALENDAR

I am currently on the initial stage of my PhD work.

The planned calendar for the tasks presented in

section 3 is the following:

 Task 1 - Conceptual Model [Jan 2009 to Aug

2009];

 Task 2 - Interaction [Sep 2009 to Feb 2010];

 Task 3 - Integration [Mar 2010 to Sep 2010];

 Task 4 - Adaptability [Oct 2010 to May 2011];

 Task 5 - Evaluation [Jun 2011 to Aug 2011];

 Task 6 - Dissertation [Sep 2011 to Dec 2011].

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