Human-Computer Interface.

William Buxton 1986

There’s More to Interaction than Meets the Eye: Some Issues in Manual Input


Imagine a time, far into the future, when all knowledge about our civilisation has been lost. Imagine further that, in the course of planting a garden, a fully stocked computer store from the 1980s was unearthed and that all of the equipment and software was in working order. Now, based on this find, consider what a physical anthropologist might conclude about the physiology of the humans of our era? My best guess is that we would be pictured as having a well-developed eye, a long right arm, a small left arm, uniform-length fingers and a ‘lo-fi’ ear. But the dominating characteristics would be the prevalence of our visual system over our poorly developed manual dexterity.

Obviously, such conclusions do not accurately describe humans of the twentieth century. But they would be perfectly warranted based on the available information. Today’s systems have severe shortcomings when it comes to matching the physical charateristics of their operators. Admittedly, in recent years there has been a great improvement in matching computer output to the human visual system. We see this in the improved use of visual communication through typography, colour, animation and iconic interfacing. Hence, our speculative future anthropologist would be correct in assuming that we had fairly well-developed (albeit monocular) vision.

In our example, it is with the human’s effectors (arms, legs, hands, etc.) that the greatest distortion occurs. Quite simply, when compared to other human-operated machinery (such as the car), today’s computer systems make extremely poor use of the potential of the human’s sensory and motor systems. The controls on the average user’s shower are probably better human-engineered than those of the computer on which far more time is spent. There are a number of reasons for this. Most of them are understandable, but none of them should be acceptable.

My thesis is that we can achieve user interfaces that are more natural, easier to learn, easier to use and less prone to error if we pay more attention to the ‘body language’ of human-computer dialogues. I believe that the quality of human input can be greatly improved though the use of appropriate gestures. In order to achieve such benefits, however, we must learn to match human physiology, skills and expectations with our systems’ physical ergonomics, control structures and functional organ.

It goes on to talk about various joysticks, trackballs, drawing toys, and lots of theoretical issues.