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Interactive multimedia into the millennium: It's time to simplify

David R Clark PhD
University of London Audio-Visual Centre

This is a most exciting time for Interactive Multimedia. There is just a chance that soon we will discover what the word means. After some 10 years in the field, I am at last beginning to understand the realities behind the rhetoric that I and others have been peddling.

As a Keynote Speaker it is my responsibility to try and set you off in the right direction. The trouble is that what I have to say may not be exactly what you want to hear. For almost the whole of its short and eventful life, our industry has been driven by technology: the needs of any prospective users have scarcely been considered, so sure have we been that with the gizmos to hand all their wishes and more could be fulfilled. We saw no real need to stop and ask.

To add to the distortion that this attitude has imposed on the marketplace, the driving technologies have been continually changing. Worse still, these changes have themselves had no necessity from the point of view of the tasks in hand.

It is a good idea to step back and review the systems that we have at our disposal in order to assess their suitability for the tasks that now seen to be paramount. In the assessment that I shall give, I pay particular attention to the origins of the technologies and their relationship to the wider world of communications. In all this there is a key concept: fitness for purpose. There is no doubt that everybody will agree when asked that the tool for the job must be fit for its purpose. But the consequences of the ready acceptance of the proposition for the multimedia industry are striking.

The first and most obvious is the removal of CD-ROM from consideration as a serious delivery system for interactive multimedia. It has always been clear from theoretical analysis that CD technology is, by virtue of its low data rate, unsuitable for the delivery of images. As is usual, however, practical demonstrations are required before most people will believe theoretical conclusions. (This is perhaps a definition of education - the more educated you are, the less you need the practical demonstration of a theoretical idea to believe and understand it.) One only has to see the painful lurchings and grindings as images are dragged from the CD-ROM in response to the slick click of a mouse to realise that the constraints on the rhythm and flow of the user's thoughts that the drive imposes render the system useless in all but the most constrained and artificial systems. And that's just for still images. With moving pictures things are hopeless, and no amount of clever coding will get over the fundamental limitations imposed by the intrinsic data rate of the standard CD.

Of course, the reason for the CD-ROM hype is not far to find. The unprecedented consumer acceptance of CDDA has brought the price of a drive down to $45 and the pressing plants have some spare capacity for short run productions. As the requirements of CD-ROM are electronically simpler than CD-DA (only error correction, not additional error concealment, is required) a high margin computer peripheral is just money for old rope. Thing to remember is that CD technology was highly optimised for just one purpose - fooling the ear. The exacting requirements of human hearing set the sampling depth and rate and the level of error fidelity. The promulgation of this as a universal standard is excellent for audiophiles but, just as your electric toaster is no use as a washing machine, CD's precise fitness for its purpose has rendered it unfit for the task of fooling another of our senses - our eyes. Many thousands of man-years have already been devoted to that task and the result is video.

Analogue video, in its old as well as its new incarnations as HDTV, is a beautifully optimised system for a particular task. One of the tragedies of the past decades has been the complete failure of those deeply involved in digital computation properly to appreciate the significance of the analogue video system. If it ain't broke, don't fix it, as they say in America, would have been a good maxim for all those who spent so much time trying to make pictures out of digits. There are undoubtedly some occasions when having an image in digital form is useful, but for the overwhelming majority of visual tasks this is not the case. The marriage of computers, an essentially minority interest, with the premier communications medium on the planet has been very unhappy. The tail has tried to wag the dog.

Another aspect of the problems confronting the multimedia industry is the failure by the practitioners to separate the concept of programme design from that of programme delivery. It must be very galling to Sony and Philips to feel that in order to sell one of their products, they must also see sold a computer that costs almost twice as much as their product. Both these companies have tried to ameliorate the problem by making computers of their own, with no success. The real truth is that a general-purpose PC is no good for delivering interactive multimedia. The Macintosh, the Amiga and the Archimedes have potential as engines for creating interactive programmes, where simultaneously there must be editors for programs and pictures, the control of peripherals such as videodisc players and overlay boards and the necessary modelling tools to construct and test the interactive programmes. The final result of these labours needs none of these things and can be delivered with its own fit for purpose delivery engine. The specification of this delivery engine has been my prime concern for the last 3 years.

As is always the case, the 'broad picture' is nothing but the sum of its fine details. If the details are not to hand the solution to the problem will be impossible. The solution will always be particular; there is no such thing as a generic solution. In your kitchen you are unlikely to have the generic cooking tool, and those expensive devices that claim to do lots of wonderful things to your food at the press of a switch are often to be found on the top shelf gathering dust. Similarly, when you call for the plumber he doesn't have in his bag a universal plumbing tool; he has a very strange collection of things, each of which is precisely fit for a particular plumbing purpose. We must not forget this lesson when we try to understand the needs of those who suspect the our interactive multimedia tools may be of some use to them in the solution of their problems. Not only must the hardware be fit for purpose, but the programme too must reflect precisely those features that the customer requires. One of the factors in the overwhelming consumer resistance to acceptance of the new technologies is that they heretofore have required an unacceptable high degree of compliance by the customer to the artificial restrictions imposed by the technology.

Looking back over the last decade is not unlike looking again at those wonderful old pictures of early flying machines with their tiers of wings and improbable engines. When I see the piles of gear on the stages, the pairs of video projectors, the LaserDisc and CD players and MIPS by the gross and the almost inevitable collapse of the demo often after a promising start, I realise that we are in the very early phase of the media revolution. I'm (almost) done with these extravaganzas because I have discovered that all the essential attributes of full interactivity can be delivered with no computer at all. As always, the simple solutions are the best.

Please cite as: Clark, D. R. (1990). Interactive multimedia into the millennium: It's time to simplify. In J. G. Hedberg, J. Steele and M. Mooney (Eds), Converging Technologies: Selected papers from EdTech'90, 1-3. Canberra: AJET Publications.

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