Many people are now using the world-wide web for distance education, as can be verified by the large number of references to this phrase on the web (over 100,000 at 27/1/99 using Alta Vista). Most web-based distance education material still uses just text material, despite the fact that normal tuition suceeds with input via many senses (e.g. visual and audio). The reason for this is that multimedia presentations are very expensive to produce, with the industry norm indicating that 1-200 hours of expert preparation are requirted for every hour of multimedia presentation. This paper introduces tools which have been developed in a University environment for producing multimedia web objects. The key feature of these tools is that they can be used by non-experts and that the preparation time for presentations is very much reduced. It can take as little as two hours of preparation for every hour of presentation for an experienced user.
The web objects are calledAudioGraphs and they can be embedded and played from an HTML environment. An AudioGraph is built from a set of zero or more images, which might for example be the slides used in a normal lecture or class (without images the model is one of the balackboard, where everything is hand drawn). Additionally an AudioGraph adds a strict sequence of annotations, which may be hand written text or diagrams (using the familiar graphics tools such as rectangle etc.), highlights and last but not least, sound clips. These annotations are recorded in the AudioGraph Recorder where both the spatial (student's view) and temporal aspects can be edited. When replayed, using the AudioGraph plugin, the images and annotations associated with each image are presented in the sequence recorded (or subsequently modified by temporal editing). Playback has very simple controls to start/stop, forward/rewind or generally position the point of playback within the AudioGraph stream.
The AudioGraph recorder and plugin have been designed with three overriding principles as a basis. These are:
This opens up their use to any teacher or lecturer who has acquired a basic computer literacy and to any student who has a modem connection to the course server. These principles differentiate the AudioGraph from other multi-media tools and data streams. At the professional end you have products such as Macromedia director, which has a steep learning curve. It provides very professional material but requires long preparation times, it therefore fails on item 1. above.. At the DIY end you have a range of ad-hoc techniques for embedding various media into web pages or presentations but the author has little scope for systematic editing and sharing of resources. Also these ad-hoc techniques also have a steep learning curve and hence fail on points 1 and 3 above.
In the AudioGraph recorder a lecturer can import presentations from applications such as powerpoint, annotate them in an intuitiave and simple editing envoronment and simply push a button to generate a structured web site of links and multimedia material. It is both easy and efficient.
Because an AudioGraph is used within a standard html environment it can be used in conjunction with other forms of teaching material, whether it be images, text or video. It can also be used within an institution's standard environment, be it local or proprietary. Where an AudioGraph wins over conventional, text and image based lecture material, is in its interactivity and in the power of synchronizing audio and visual material. Although text based notes can enhance an image, the input to the student (via the visual sense alone) is either the text or the image and not both simultaneously. Only when using an AudioGraph or similar tool can simultaneous media input can be provided, where the student listens and sees at the same time. This reinforcement is an age-old techniques used by teachers since at least the middle ages.
AudioGraphs can and havbe been used to replace formal lectures, even in situations where distance is not an issue. They can also be used very effectively to provide tutorial materials, where assignments or examples can be worked through with explanations. Their use can also liven up what is normally a pretty dull and solitary learning experience, that of browsing paper-based lecture notes, which is still the method of delivery for many extramural programs.
The AudioGraph is not just a vision; it is a fledgling reality. Massey University(NZ), in cooperation with Surrey University (UK) have been developing tools and have been deploying AudioGraphs for some years. The prototype tools [1] were very basic and used Java applets for playback. Although they met requirement 1 above, they did not meet requirements 2 and 3. Java applets were unable to decompress sound in real time and so the prototype AudioGraphs (examples can be found at [2-4]) required around 1Mbyte per minute of recorded material, depending on the audio density. The Visual basic recorder also had very little in the way of editing facilities.
Current AudioGraphs [5] on the other hand, are produced by an advanced C++ application with extensive editing facilities and the playback is achieved using plug-in technology. The enhanced speed of a plug-in module allows us to use state-of-the art compression techniques, such as PNG for graphics and GSM for sound. The result of this recent work are AudioGraphs that require an order of magnitude less data bandwidth and stream at approximately 100Kbytes per minute, depending on audio and image density. (examples can be found at [6-8]). The only dissadvantage of the plugin approach is that software must be explicitly downloaded prior to playback and placed in the browsers plugin folder. Using Java, the download of the player was hidden from the user but of course required additional download time.
All software is currently available from the projects web [9].
Two papers have been written on the evaluation of the use of AudioGraphs in University Teaching [10,11], the second includes the results of a formal survey given to students taking AudioGraphic tuition in place of lectures when studying internally. The results of this survey were quite surprising, for we had expected an adverse reaction from the students due to being deprived of their formal lectures. However, the more mature students that responded in the survey, felt that overall, this technique of information delivery was somewhat better than a conventional lecture.
[1] Jesshope, C.R. and Shafarenko, A., 1997, Web Based Teaching: a minimalist approach, Proc. Second Australasian Conference on Computer Science Education, ISBN: 0-89791-958-0, pp16-23 (see also http://www.ee.surrey.ac.uk/Research/DLearn/massey-mirror/)
[2] Shafarenko, A/. 1996, Lecture notes in Discrete mathematics, http://www.ee.surrey.ac.uk/Teaching/Courses/MathComp/
[3] Marshall, P 1996, Tutorials in Motors and Transformers, http://www.ee.surrey.ac.uk/Teaching/Courses/DCMotors/
[4] Murphy, L. and Fligelstone, R, Parametric representation of curves and relative motion, http://mcs.open.ac.uk/otd/liz2/
[5] Jesshope, C., Shafarenko, A and Slusanschi, H. 1998 Low-bandwidth multimedia tools for web-based lecture publishing, IEE Engineering Science and Educational Journal, 7 (4), pp148-154. (see also http://fims-www.massey.ac.nz/~audiogph/)
[6] Jesshope, C., A brief AudioGraph on the AudioGraph http://www.ee.surrey.ac.uk/Research/DLearn/massey-mirror/aeps/Audiograph.htm
[7] Jesshope, C., 1998, AudioGraphic AudioGraph documentation, http://www.ee.surrey.ac.uk/Research/DLearn/massey-mirror/aeps/Audiograph.htm
[8] Jesshope, C., 1998, Advanced Computer Systems, an honours course in computer architecture with extensive use of AudioGraphs http://fims-www.massey.ac.nz/~crjessho/comp_arch/
[9] Jesshope, C. 1998, AudioGraph downloads site, http://fims-www.massey.ac.nz/~audiogph/htdocs/Download.html
[10] Pearson, M. and Jesshope, 1988 C., Multi-campus teaching using computer networks, Proceedings of the Third Australasian Conference on Computer Science Education pp 106 - 111, July 1998.
[11] Segal, J, 1997, An Evaluation of a teaching package constructed using the AudioGraph, a web-based lecture recorder, ALT-J, 5,(3) pp32-42.
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The Audiographs article would be more interesting if it discussed the results of the study on student reaction to audiographs mentioned in the final paragraph rather than a discussion of the software itself. Based on the author's description of the Audiograph software, it is similar to such products as Astound produced by Gold Disk, Inc. It is not unique or even particularly cutting edge (I learned how to use Astound more than five years ago).