Tipos de instrumentos utilizados en las dinámicas habituales en EF

The learning compute r should be designed and built on a modu lar basis , with sepa rate interface, application logic a nd data management layers. To fu rther facilitate maintenance and reusability, distinct log ica l functions within each of these layers should be i mplemented in separate software mod u les.

A req uirement of the learning computer is that it teaches a topic in a n u mber of a lternative study m odes. These modes a re defined by a unique su bset of elements , each of which encapsulates a specific learning a rtefact . This modularity wou ld suggest that the component a pproach to assembling interfaces, popularised by rapid a pplication development ( RAD) environments like Delphi and Visual Basic (Osier et a l . ,

1 997, p. 4 ) , is a good fit for build ing a n Integrated Interface. Study modes ca n then be i mplemented throug h a mech anism for selecting from a pre-installed set of learn ing components (Fig u re 5.6 ) .

Dewire ( 1 998, pp. 1 98-99) describes a component as a reusable software module,

designed to be used with in another application ca lled a container. lt may cons ist of one class, be a composite of several classes, or be an entire application . In contrast to an o bject, whose code m u st be accessible for the object to be used, a com ponent is designed so that it can be u sed without modificatio n s to its sou rce code.

With a RAD approach each learning element can be implemented as a sepa rate software component encompassing the necessary functionality. The following fu nctionality may be p rovided by the component:

• customising a general-purpose tool provided by the underlying o pe rating

system (e. g . a media player) ;

• linking to a separate a pplication installed on the user's mach ine or accessed via the network (e. g . an adaptive tutoring application); o r

• encapsulating a m ore soph isticated, p u rpose-built learning tool utilising new

educational technologies (e.g . XML-based learning objects).

A learn ing component u ses the same general form to d isplay different conte nt to the student at different points in a course. Conversely, d ifferent learning components map the same general learn ing content to d ifferent forms at the same point in a cou rse . The

Chapter 5 : Towards a specification 1 0 1

learning com puter maps the appropriate data file to a component.

N ot all elements of the learning computer interface embody learning tasks. Some perform system management tasks such as capturing logon or other information about the student, or to enable the student to navigate the course and access d ifferent study modes. These should also be implemented as reusable software components.

Learning by lecture

Lecture Lecture Notes Learning Goals Group Work

Tutorial Student Notes Assignment Study Guide

Learning by T utorial

Lecture Lecture Notes Learning Goals Group Work

Tutorial Student Notes Assignment Study Guide

Figure 5.6: Modes implemented by selectin g from pre-i nsta lled components.

Just-in- Time Help

To provide help in u sing the various elements of the system, a Help compo ne nt should be linked to every i nterface element. This component should provide specific, context­ sensitive help on using the particular interface element. lt should not merely p rovide a path to an overall help system , which the u ser m ust try to navigate to find what they are looking for.

In the Delphi RAD environ ment, very specific h e lp on a com ponent is p rovided to the user ( i . e. the program mer) by their selecting the component with the mouse and clicking the "F 1 " key ( l n prise, 1 999b, pp. 2.1 1 -1 2). In an analogous way, I M M E D IATE should provide just-in-time, just enough information for using a component whenever the u ser ( i . e . the student) selects that component and clicks the " F 1 " key.

Chapter 5 : Towards a specification 1 02

5 . 5 . 1 System Components

The Learning Shell is requ i red to manage Windows fu nctions l i ke fi le input and output, document printing, the opening and closing of screen windows, and networking , in such a way as to render the operating system invisible to the learner. This requires an intermed iate level between the learning computer i nterface and the operating system. This system level is required for translating and synchronising actions between the domain-oriented objects a nd interactions of the Learn ing Shell and the generic file­ oriented fu nctions of the operating system . To facilitate modification a nd re-use the system level should also have a modul a r design .

Interface components

t

Controller

Model Layer

Operating system

Fig u re 5.7 : Lea rn ing Shell System components.

The essentia l parts of the system level a re shown in F igure 5.7. They consist of a Controller o bject a nd a model layer. The Controller object provides an API through which interface components interact with each other a nd with the system level. it plays a n analogous role to a browser's controller, wh ich manages the other components and calls on the m to perform o perations specified by the user (Comer, 1 999, p. 427). The learn ing computer Control ler, however, has additional capacities to manage the interface for the user, through reference to the model layer.

The model layer is a set of data structures and related operations, each of wh ich models a d ifferent aspect of the learn i ng computer. These data structures together

Chapter 5 : Towards a specification 1 03

with each other correctly and with the Windows file syste m .

T h e reference model incorporates t h e System Tree, a hierarchica l structure modelling the cou rse table of contents. The System Tree provides the basis for navigation to different sections and topics with in the cou rse and records the student's prog ress through the course , u sing a traffic light metaphor (Figure 5.8). Changing position in the System Tree does not change the student's study mode.

The reference model stores information about each study mode and learning component offered by a course. This provides the basis for swapping between study modes within the cou rse. Changing study mode does not change the student's position in the System Tree. The reference model also models the d i rectory system conta i n ing course learning resou rces. lt maps a learning component to its correct resource file.

To facilitate i ndivid ualisation, the model level must model the student as well as the system . lt therefore includes a Student Model , which stores information about the user needed by the learn ing computer that wou ld not otherwise be available. The Student Model is discussed further in the next section.

Figure 5.8: System T ree models table of contents and student's prog ress.