The Sliding Present   

Continuing advances in browser technology, object oriented Web- based programming, and software agent research will continue to provide innovative mechanisms to enhance active learning in Web- based courses.

Plug-In Modules

Netscape Communications Corporation has defined an Application Programmers Interface (API) which enables software suppliers to write operating system specific plug-in modules to seamlessly integrate diverse media types not directly supported by the browser within an embedded browser window.

For example, the Macromedia Shockwave plug-in enables Macromedia Director tm files to be played in an embedded browser window. Although a great deal of educational multimedia already exists in the Macromedia Director tm format, compression techniques must improve before this technology becomes practical on a large scale.

None-the-less, plug-in modules support the embedded integration of a wide range of other media types conducive to creating Web pages with educational content. These plug-ins include the Virtual Reality Modelling Language (VRML), Quicktime tm Movies, Adobe tm Portable Document Format (PDF) , and others. These should enhance existing courseware at the expense of introducing inconsistency and incompatibility if the appropriate plug-in is not installed or otherwise unavailable for a given platform.

Object Oriented Web Programming

The Java programming language is an object oriented, vendor neutral, multi-threaded language which compiles to a machine independent pseudo-code. Pseudo-code and data are transmitted from the server to the client where it is executed by an interpreter running within the browser. Small applications called applets, and any data are stored at the server are executed on the client side of the transmission link in an embedded window. In many cases this will improve the quality and performance of animation sequences since animations are not constructed on the server and then down loaded frame by frame.

One example in using Java has been to demonstrate the Digital Differential Analyzer (DDA) and Bresenham's algorithm for line drawing (Figure 2). The mouse is used to designate the end-points of a line in the applet window. Enlarged pixels are then drawn along the line determined by the algorithm. Because the same applet implements both the DDA and Bresenham's Algorithms, students can compare the results against the supplied source code. 


     
Active Learning Line Drawing Algorithm.

              Fig. 1 : Active Learning Line Drawing Algorithm.



     
Interactive Syntax Analysis Example.

    
            Fig. 2 : Interactive Syntax Analysis Example.
Another example shown in Figure 2, presents to a student the syntax of an integer, and the pseudo-code which would parse it. The student can then enter any number and, step by step, see the paths and code which would be traversed to check the syntax of the entered data. The student has control of the demonstration. Similar examples have been developed for the parsing of other data types as well as interactive examples of binary operations, various sorting algorithms and various searching algorithms.

It is indicated that these interactive example applets, when supplied with source code in the context of online course notes should further enhance aspects of active learning.