Fig. 1 : A laboratory exercise examining ambient, diffuse and specular characteristics of light.
Initial critics of Web-based courseware questioned the motivation for providing information in an electronic format which duplicated documents already available in printed form. These critics argued that the WWW relegated the computer to the role of an expensive electronic page-turner, using technology for technology's sake rather than for sound educational reasons.
Since their introduction, the functionality of Web Browsers has evolved [Khare 1996; Hill et al 1995] , and with them the approaches used to create Web-based courses. Most browsers now provide mechanisms for application integration and for extending the set of supported media types [von Konsky 1996; Berghel 1996a] . While some argue that the proliferation of browser extensions has muddied the tidy concept of hypertext uniformity across multiple platforms, these extensions enable functionality to be added to Web courseware not available in printed documents or their strict electronic equivalents.
Application integration enables Web courseware to extend browser capabilities and support active learning [Woolf and Hall 1995], where students learn through experimentation and guided expeditions through instructional material [Watson 1996] .
This approach has been adopted in a first year tertiary unit on engineering graphics. Interactive laboratory exercises are integrated into other
online course material. In one module, students learn about rendering by
entering a textual description of a scene into a browser form.
The text describes the geometry, material properties, lighting
characteristics, and viewing details of a given three-dimensional
environment. When submitted, the texutal description is
transmitted to the server where it is parsed and rendered by the POV-Ray software application. The resulting image is transmitted back to
the client station where it is displayed in the browser window.
A typical textual description and the image generated when the
form is submitted is shown in Figure 1. A more interactive
approach would be to generate VRML-2.0 which would be displayed
by a browser application.
By following backward links to the form, rendering parameters may be altered and the effect studied. Feedback from students suggests that this approach enables them to understand the significance of material attributes like the ambient, diffuse and specular properties of a material when they have been given an opportunity to study their effect through direct experimentation.
Fig. 1 : A laboratory exercise examining ambient, diffuse and specular characteristics of light.
In another module on Constructive Solid Geometry, students build complex shapes by combining union, intersection, and difference operations on simple shapes. In other modules, students learn about graphing and plotting, and the generation of three-dimensional surfaces. In all cases, anecdotal evidence suggests that students better understand a given subject when instructional material is supplemented with practical experience acquired through direct experimentation and active learning.
