A Specialised User Shell

The goal of the learn ing computer is to simplify the computer environ ment a nd render the i nterface invisible to the u ser. In this sectio n , the tech n ical outlines for meeting these req u i rements within a Windows framework are discussed. The student view of the learn ing computer is a specia l-purpose, direct-manipulation, graphical i nterface , which provides all the functionality needed for a user to com plete a task in the learning domain.

To achieve this it is necessary to remove any visual garbage not directly relevant to the task at hand . General-pu rpose featu res and functions associated with the operating system or a web browser, that a re not needed to accomplish a task in this domain , shou ld be treated as a distraction and not be made available.

In a Windows context, this mea n s:

• p reventing the user from accessing or being distracted by general-purpose

featu res such as the Desktop and the directory system ;

• rem oving the standard menus a nd toolbars associated with individual windows, including web browser wi ndows; and

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Approach Possible Comments

implementation

Specialised machi ne General purpose PC that is The "visual garbage" would only used for a single purpose. still be there. Not realistic to

expect it to remain single

purpose in the home

en vi ronm ent.

Specialised user profi le User profile with specialised Goes beyond options availa ble

system setti ngs i . e. for Windows profiles. More

customised desktop and realistic on Linux which has

directory view unique di rectory system for

each user and can be

customised to meet special

requirements. Does not hide

superfluous features and functions.

Specialised application A Windows application with Simplest implementation. Can

standard menus etc removed. be readily i nstalled on a ny machine using same operating system . User still withi n the

Windows environment. Speciali sed operating system Dual boot Windows/Linux with Requires skilled installation

a customised Linux GUI as learning com puter.

Specialised user shell Superim poses own desktop Can be installed as an

over the operating system application, but shuts out the

desktop. User can access general Windows

operating system features and environment.

functions only through the

specialised shell

Table 5.2: Possible methods for rendering the interface i nvisible.

• limiting generic fun ctions like electronic mail and web browsing to the cu rrent learning domain.

Five possible methods have been considered for implementing these requirements on a PC runn ing some version of the Windows operating system (Table 5.2):

• A single-use computer. I mplementing a sing le-use Windows-based PC approach

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for learning. All Windows genera l-purpose fu nctions and featu res wou ld remain accessible .

• A special-purpose user profile. Windows operating systems allow u ser profiles to be

set up wh ich restrict what is displayed on the Desktop and what data files can be seen by a particular user. All prog ra ms installed on the machine can be accessed , however, as can all their general-purpose features a nd functions. lt is not realistic to expect all extramural students to be able to set up and maintain their own user profile for lea rn ing .

• A special application. I nsta llation wizards have made it possible for relatively i nexperienced computer users to insta l l Windows appl ications. A special appl ication ca n be presented through a custom interface without all the standard Windows features like menus and taskbars. H owever, the learner is still working with in the overall o perating system environ ment whose complexities and d istractions are just a mouse-click o r keystroke away.

• A specialised operating system with a dual-boot PC. Ope rating systems are

implemented on at least two levels - an inner kernel containing the functionality, a nd an outer user command interface, or shell, through which the user interacts with the kernel functionality (Fiynn et a l . , 1 997, pp. 4-7, Brookshear, 2003, pp. 1 13-

1 1 5) . Modern operating systems offer a direct manipu lation graphical user shel l .

Linux, with its open source code a nd a separately-ava ilable kernel, has been designed so that programmers can add their own user shell ( Dyer, 2004). In theory, the learning computer cou ld be implemented as a specia lised user shell for the Linux operating system. However, to run on a Windows-based PC would mean creating a dual-boot system by pa rtitioning the computer's hard d rive a nd installing the specialised operating system in the space created (Hall et a l . , 2000, p. 54). This

is way beyond what can be asked of a typical home computer user.

• A special-purpose graphical user shell for Windows. Another possibility is to add a

special-purpose user shell to Windows. I mplementing this shell is more problematic than in Linux, because Microsoft's proprietary system does n ot provide an open sou rce or kernel-only version that would allow its GUI to be easily replaced by a custom version. lt, therefore, would have to be superi m posed over the Windows G U I in such a way that Windows becomes invisible to the user.

F rom reviewing these alternatives it was concluded that the best approach for i mplementing the learning computer would be as a special-pu rpose user shel l . Thi s could b e done most cleanly a s a Linux-based implementation . B u t t o meet the

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req u i reme nts that the learning computer be simple to install and run from the Windows environ ment, the best solution was for I M M E D IATE to be implemented as a special ised g raph ical user shell - a Learning Shell - over the Windows operating system .