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Introduction

21 January, 2016 - 14:46

The design and implementation of e-Learning platforms is essential for the development and future of information and communication technologies in knowledge management in the teaching/learning process. Universities and companies require a methodology for developing versatile and flexible e-Learning applications that are, at the same time, capable of storing the large volumes of information required by these educational processes and efficiently conveying this information to their users. This situation is a catalyst revealing the vital need for the efficient and timely development of a teaching/learning process based on e-Learning platforms that takes into account the needs of the student/teacher and achieves optimum quality. To achieve this goal a methodology is required that standardizes the conception, design and implementation of this type of systems based on the creation of basic artefacts that can be used equally well across the different platforms developed. The methodology proposed should be based on a systematic approach for the development of e-Learning systems considering systematic methods coming from both e-Learning and software development communities, involving a series of stages each containing work flows and phases and a set of artefacts (cards, reports, templates, etc.) that can form the basis of the design and development of any e-Learning platform. By doing so, we aim at the development of, what we have named, a Model-Based Instructional System Development Environment (Mb-ISDE), to include e-Learning development in the current trends of model-based software development.

In this chapter, our interest is focus on platform-independent models useful for e-Learning development and concretely on the Task & Domain models, these models will be analyzed in detail and how we they are used for the development e-Learning systems following a model-based instructional system development.

Our proposal, Model-Based Instructional System Design Environment contains several and different models and these models can be divided and classified into different ways based on multiple criteria.

Currently, creating product software, and e-Learning software is not an exception, comes with a lot of compatibility issues. Existing application landscapes within e-Learning consist of a lot of different applications, facilities, operating systems, programming languages, etc. In an ideal scenario new software build in such a context is compatible with all existing and future systems. Users of professional software shouldn't have to deal with compatibility issues. However, there are simply too many platforms in existence, and too many conflicting implementation requirements, to ever agree on a single choice in any of these fields. The solution of the current software engineering proposals is Model-Driven Development(MDD) (OMG, 2003).

The Model-Driven Development specifies three models on a system, a computation independent model; a platform independent model and a platform specific model (see Figure 15.1).

1.The computation independent model (CIM) focuses on the on the environment of the system, and the requirements for the system. The details of the structure and processing of the system are hidden or as yet undetermined.

2. The platform independent model (PIM) focuses on the operation of a system while hiding the details necessary for a particular platform. A platform independent model shows that part of the complete specification that does not change from one platform to another. The Platform Independent Model can be compared to the ontological system notion. Ontology is independent implementation by definition.

3. The platform specific model (PSM) combines the platform independent model with an additional focus on the detail of the use of a specific platform by a system.

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Figure 15.1 User interface Platform models 

In this chapter we will treat the PIM models and in especially the Task and Domain models inside of this platform. Previous models are usually stored in an XML-based when a user interfaces description language is used, for instance UsiXML. Our main goal is that our domain model will contain references and learning objects. In the other side, our task model will represent those tasks the user will be allowed to perform by using the user interface, and the temporal constraints between these tasks. Under these considerations, in this chapter, we introduce the task and domain model of our Mb-ISDE process. These units allow the construction of e-Learning systems by defining and relating these user tasks and domain objects to presentation and dialog interface models.

In an e-Learning environment many different activities or tasks can be carried out. In this context, a task model is often defined as a description of an interactive task to be performed by the learners of an e-Learning application through the e-Learning application’s user interface. In this kind of applications there are tasks performed by a single user, but there also some tasks carried out in collaboration. Therefore, a task model is required with collaborative tasks support. In these collaborative environments activities include coordination, cooperation, collaboration and communication tasks. In our proposal we are using ConcurTaskTrees (Paternò F. , 2002) and CUA (Pinelle, Gutwin, & Greenberg, 2004) notations in order to support the specification of e-Learning and groupware tasks. While CTT is enough for regular tasks specification, it is complemented with CUA to include this collaborative tasks requirements specification. Our eLearniXML notation includes all these task requirements as all the cooperative and communicative task requirements presentationnecessary for covering an e-Learning system use.

So, our task model proposal is inspired notations and standards already available, where specific needs and constraint s imposed by e-Learning systems have been identified. Thus, the proposed task model is based on notations as ConcurTaskTrees (Paternò F., 2002), UML and description languages recent user interfaces using CTT notation, such as (UsiXML) and FlowiXML (Guerrero García, Vanderdonckt, & González Calleros, 2008).

In a similar way, our domain model, which traditionally accompanies the proposals to develop user interfaces based on models, is syntactic and semantic. Learning objects and relationships among them will be treated in this chapter. But domain model is not useful for that, domain model is also useful for specify additional featured elements of e-Learning (see Figure 15.2).

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Figure 15.2 Task and domain models position for developing an e-Learning system, (Fardoun, 2009)