SBHD: What with the delays, videophones have proved a disappointment to the techno-driven, but the ISDN network may change that, at a price. Michael Evamy reports
Have you put your videophone back in its box yet? According to new research by psychologists, calls that involve tasks such as explaining a route would be quicker and lead to less confusion if they were made down a traditional phone instead.
The researchers at the University of Nottingham also add that British Telecom should consider abandoning colour videophone screens until the signal transmission technology improves. Black and white screens could improve the quality of the picture and the quality of the communication.
The findings could be damaging to BT’s videotelephony business, which launches a brand new desktop model next month designed for use on the high-speed digital ISDN network.
Anyone who has made a call using BT’s standard analogue-based videophone, the Relate 2000, will know the problem. The data needed to transmit colour images has to be compressed in order to be sent down analogue phone lines, and this leads to a delay of up to half a second in receiving both the video and voice signals. The effect is akin to making a transatlantic call ten years ago, with all its implicit awkward pauses and interruptions.
Claire O’ Malley, a psychologist at the Centre for Research in Development, Instruction and Training at the University of Nottingham, led the tests which took 24 pairs of subjects, and split them up: one person was given the task of describing a route on a map to their partner at the other end of a videophone link.
“In terms of task performance,” says O’Malley, “unless there is a delay, it doesn’t matter whether you can see each other. Once there is a delay, it has a big impact; it affects accuracy, even though you don’t actually take longer. We believe, from our analyses of the conversations, that that can be put down to the difficulties in communication.
“Currently videophone technology has a delay. This is the case even with ISDN. People have a problem in the transmission of verbal information because it’s hard to judge the length of pauses. but because they can see each other they try to compensate by using the visual channel, by looking and nodding. But they can’t judge the timing of that either, so they’re at a double disadvantage.”
The screen size also limits communication, says O’Malley. When it is just a few square inches, as on the Relate 2000, users have the choice of seeing their partner’s face clearly, or their gestures, but can never see both well. “Designers should think not just about the compression and sending more data, but how they can get away with sending less. The most important information you need to receive is about the timing of gestures and whether someone is looking at you. You can convey that just as well in black and white, which you can send very fast with good definition.”
Observers say the shortcomings of existing analogue videophones for consumer markets may have damaged sales and expectations irreparably, although BT claims to have sold thousands of the Relate 2000. “Two years ago, European manufacturers were optimistic,” says Diane Trivett, an analyst at business information consultancy Dataquest. “But when I surveyed the same companies six months ago, the optimism had gone, and two, including Philips, had withdrawn completely. They haven’t caught on at all. Now, when we ask them what applications they see for the ISDN network, they mention videophones, but add that no-one wants them because of the cost and quality – ISDN quality is variable in different countries.”
BT claims to have eliminated the delay problem on Presence, its new ISDN videophone for the business market. Random Product Design was responsible for its design, as it has been for the Relate range. Random’s Gus Desbarats says Presence has a bigger screen and higher resolution picture, thanks to ISDN. But it will cost between Ãº1500 and Ãº2000.
So much for the businesses with one of the 350 000 lines served by ISDN in the UK, but the number of homes with ISDN is negligible. One BT spokesman remains defiant in the face of the gloomy predictions, claiming the future will bring a revolution in videotelephony similar to that of mobile phones. It’s true that a consumer might forgive problems with delays and jerkiness, if they can see a moving picture of their new0 grandchild in Australia, for example. But it’s hard to see consumers coughing up for a videophone unless a reasonable number of the people they call also have one.
The “revolution” could be slow.